251 files changed, 376 insertions, 374 deletions

diff --git a/nuget.config b/nuget.config
index 34dfa486..b7e5add1 100644
--- a/nuget.config
+++ b/nuget.config
@@ -15,7 +15,7 @@
     </packageSource>
     <packageSource key="build">
       <package pattern="WixToolset.*" />
-      <package pattern="WixBuildTools.*" />
+      <package pattern="WixInternal.*" />
     </packageSource>
   </packageSourceMapping>
 </configuration>
diff --git a/src/api/burn/test/BalUtilUnitTest/BAFunctionsTests.cpp b/src/api/burn/test/BalUtilUnitTest/BAFunctionsTests.cpp
index 9920564e..2ae539ee 100644
--- a/src/api/burn/test/BalUtilUnitTest/BAFunctionsTests.cpp
+++ b/src/api/burn/test/BalUtilUnitTest/BAFunctionsTests.cpp
@@ -4,8 +4,8 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace BalUtilTests
 {
diff --git a/src/api/burn/test/BalUtilUnitTest/BalUtilUnitTest.vcxproj b/src/api/burn/test/BalUtilUnitTest/BalUtilUnitTest.vcxproj
index d6c03a43..94586fbd 100644
--- a/src/api/burn/test/BalUtilUnitTest/BalUtilUnitTest.vcxproj
+++ b/src/api/burn/test/BalUtilUnitTest/BalUtilUnitTest.vcxproj
@@ -3,7 +3,7 @@
 
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.props" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.props" />
 
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -61,5 +61,5 @@
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.targets" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.targets" />
 </Project>
diff --git a/src/api/burn/test/BalUtilUnitTest/BootstrapperApplicationTests.cpp b/src/api/burn/test/BalUtilUnitTest/BootstrapperApplicationTests.cpp
index 396682ee..70b01a42 100644
--- a/src/api/burn/test/BalUtilUnitTest/BootstrapperApplicationTests.cpp
+++ b/src/api/burn/test/BalUtilUnitTest/BootstrapperApplicationTests.cpp
@@ -4,8 +4,8 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace BalUtilTests
 {
diff --git a/src/api/burn/test/BextUtilUnitTest/BextUtilUnitTest.vcxproj b/src/api/burn/test/BextUtilUnitTest/BextUtilUnitTest.vcxproj
index c27fb442..d437dc36 100644
--- a/src/api/burn/test/BextUtilUnitTest/BextUtilUnitTest.vcxproj
+++ b/src/api/burn/test/BextUtilUnitTest/BextUtilUnitTest.vcxproj
@@ -2,7 +2,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.props" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.props" />
 
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -57,5 +57,5 @@
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.targets" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.targets" />
 </Project>
diff --git a/src/api/burn/test/BextUtilUnitTest/BundleExtensionTests.cpp b/src/api/burn/test/BextUtilUnitTest/BundleExtensionTests.cpp
index fde9d2b6..5c5c5812 100644
--- a/src/api/burn/test/BextUtilUnitTest/BundleExtensionTests.cpp
+++ b/src/api/burn/test/BextUtilUnitTest/BundleExtensionTests.cpp
@@ -4,8 +4,8 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace BextUtilTests
 {
diff --git a/src/api/burn/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs b/src/api/burn/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
index 39a92024..7074c166 100644
--- a/src/api/burn/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
+++ b/src/api/burn/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Mba.Core
     using System;
     using System.Collections.Generic;
     using System.Runtime.InteropServices;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Mba.Core;
     using Xunit;
 
diff --git a/src/api/burn/test/WixToolsetTest.Mba.Core/WixToolsetTest.Mba.Core.csproj b/src/api/burn/test/WixToolsetTest.Mba.Core/WixToolsetTest.Mba.Core.csproj
index 7aeb8aad..7c21734f 100644
--- a/src/api/burn/test/WixToolsetTest.Mba.Core/WixToolsetTest.Mba.Core.csproj
+++ b/src/api/burn/test/WixToolsetTest.Mba.Core/WixToolsetTest.Mba.Core.csproj
@@ -13,6 +13,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/api/wix/test/WixToolsetTest.Data/SerializeFixture.cs b/src/api/wix/test/WixToolsetTest.Data/SerializeFixture.cs
index 98317446..8c8a23b4 100644
--- a/src/api/wix/test/WixToolsetTest.Data/SerializeFixture.cs
+++ b/src/api/wix/test/WixToolsetTest.Data/SerializeFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Data
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Data;
     using WixToolset.Data.Bind;
     using WixToolset.Data.Symbols;
diff --git a/src/api/wix/test/WixToolsetTest.Data/WindowsInstallerTableDefinitionsFixture.cs b/src/api/wix/test/WixToolsetTest.Data/WindowsInstallerTableDefinitionsFixture.cs
index efb777ee..71775fa2 100644
--- a/src/api/wix/test/WixToolsetTest.Data/WindowsInstallerTableDefinitionsFixture.cs
+++ b/src/api/wix/test/WixToolsetTest.Data/WindowsInstallerTableDefinitionsFixture.cs
@@ -2,7 +2,7 @@
 
 namespace WixToolsetTest.Data
 {
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Data.WindowsInstaller;
     using Xunit;
 
diff --git a/src/api/wix/test/WixToolsetTest.Data/WixToolsetTest.Data.csproj b/src/api/wix/test/WixToolsetTest.Data/WixToolsetTest.Data.csproj
index 8198ac8f..ea26bea8 100644
--- a/src/api/wix/test/WixToolsetTest.Data/WixToolsetTest.Data.csproj
+++ b/src/api/wix/test/WixToolsetTest.Data/WixToolsetTest.Data.csproj
@@ -12,6 +12,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/burn/test/BurnUnitTest/BurnTestException.h b/src/burn/test/BurnUnitTest/BurnTestException.h
index e813f95c..b9467926 100644
--- a/src/burn/test/BurnUnitTest/BurnTestException.h
+++ b/src/burn/test/BurnUnitTest/BurnTestException.h
@@ -13,7 +13,7 @@ namespace Test
 namespace Bootstrapper
 {
     using namespace System;
-    using namespace WixBuildTools::TestSupport;
+    using namespace WixInternal::TestSupport;
 
     public ref struct BurnTestException : public SucceededException
     {
diff --git a/src/burn/test/BurnUnitTest/BurnTestFixture.h b/src/burn/test/BurnUnitTest/BurnTestFixture.h
index 470c81c1..35acba67 100644
--- a/src/burn/test/BurnUnitTest/BurnTestFixture.h
+++ b/src/burn/test/BurnUnitTest/BurnTestFixture.h
@@ -13,7 +13,7 @@ namespace Test
 namespace Bootstrapper
 {
     using namespace System;
-    using namespace WixBuildTools::TestSupport;
+    using namespace WixInternal::TestSupport;
 
     public ref class BurnTestFixture : IDisposable
     {
@@ -31,7 +31,7 @@ namespace Bootstrapper
 
             PlatformInitialize();
 
-            this->testDirectory = WixBuildTools::TestSupport::TestData::Get();
+            this->testDirectory = WixInternal::TestSupport::TestData::Get();
 
             LogInitialize(::GetModuleHandleW(L"BurnUnitTest.dll"));
 
diff --git a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
index fe86f042..46708c26 100644
--- a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
+++ b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
@@ -2,7 +2,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.props" />
+  <Import Project="..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.props" />
 
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -99,5 +99,5 @@
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <Import Project="..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.targets" />
+  <Import Project="..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.targets" />
 </Project>
diff --git a/src/burn/test/BurnUnitTest/RegistrationTest.cpp b/src/burn/test/BurnUnitTest/RegistrationTest.cpp
index 869e5114..f95c011f 100644
--- a/src/burn/test/BurnUnitTest/RegistrationTest.cpp
+++ b/src/burn/test/BurnUnitTest/RegistrationTest.cpp
@@ -23,7 +23,7 @@ namespace Bootstrapper
     using namespace System;
     using namespace System::IO;
     using namespace Xunit;
-    using namespace WixBuildTools::TestSupport;
+    using namespace WixInternal::TestSupport;
 
     public ref class RegistrationTest : BurnUnitTest, IClassFixture<TestRegistryFixture^>
     {
diff --git a/src/burn/test/BurnUnitTest/RelatedBundleTest.cpp b/src/burn/test/BurnUnitTest/RelatedBundleTest.cpp
index 3d1964c3..310a958a 100644
--- a/src/burn/test/BurnUnitTest/RelatedBundleTest.cpp
+++ b/src/burn/test/BurnUnitTest/RelatedBundleTest.cpp
@@ -16,7 +16,7 @@ namespace Bootstrapper
     using namespace System;
     using namespace System::IO;
     using namespace Xunit;
-    using namespace WixBuildTools::TestSupport;
+    using namespace WixInternal::TestSupport;
 
     public ref class RelatedBundleTest : BurnUnitTest, IClassFixture<TestRegistryFixture^>
     {
diff --git a/src/burn/test/BurnUnitTest/TestRegistryFixture.cpp b/src/burn/test/BurnUnitTest/TestRegistryFixture.cpp
index 89704d09..fe82c4af 100644
--- a/src/burn/test/BurnUnitTest/TestRegistryFixture.cpp
+++ b/src/burn/test/BurnUnitTest/TestRegistryFixture.cpp
@@ -165,7 +165,7 @@ LExit:
     return ls;
 }
 
-namespace WixBuildTools
+namespace WixInternal
 {
     namespace TestSupport
     {
diff --git a/src/burn/test/BurnUnitTest/TestRegistryFixture.h b/src/burn/test/BurnUnitTest/TestRegistryFixture.h
index 2f283f3e..da070680 100644
--- a/src/burn/test/BurnUnitTest/TestRegistryFixture.h
+++ b/src/burn/test/BurnUnitTest/TestRegistryFixture.h
@@ -1,7 +1,7 @@
 #pragma once
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools
+namespace WixInternal
 {
 namespace TestSupport
 {
diff --git a/src/clean.cmd b/src/clean.cmd
index d0d9ebd8..0eacc32c 100644
--- a/src/clean.cmd
+++ b/src/clean.cmd
@@ -17,8 +17,9 @@ if exist global.json (del global.json)
 if exist ..\Directory.Packages.props (del ..\Directory.Packages.props)
 if exist ..\global.json (del ..\global.json)
 
-if exist "%_NUGET_CACHE%\wixbuildtools.testsupport" rd /s/q "%_NUGET_CACHE%\wixbuildtools.testsupport"
-if exist "%_NUGET_CACHE%\wixtoolset.basebuildtasks.sources" rd /s/q "%_NUGET_CACHE%\wixtoolset.basebuildtasks.sources"
+if exist "%_NUGET_CACHE%\wixinternal.basebuildtasks.sources" rd /s/q "%_NUGET_CACHE%\wixinternal.basebuildtasks.sources"
+if exist "%_NUGET_CACHE%\wixinternal.testsupport" rd /s/q "%_NUGET_CACHE%\wixinternal.testsupport"
+if exist "%_NUGET_CACHE%\wixinternal.core.testpackage" rd /s/q "%_NUGET_CACHE%\wixinternal.core.testpackage"
 if exist "%_NUGET_CACHE%\wixtoolset.bal.wixext" rd /s/q "%_NUGET_CACHE%\wixtoolset.bal.wixext"
 if exist "%_NUGET_CACHE%\wixtoolset.balutil" rd /s/q "%_NUGET_CACHE%\wixtoolset.balutil"
 if exist "%_NUGET_CACHE%\wixtoolset.bextutil" rd /s/q "%_NUGET_CACHE%\wixtoolset.bextutil"
@@ -28,7 +29,6 @@ if exist "%_NUGET_CACHE%\wixtoolset.core" rd /s/q "%_NUGET_CACHE%\wixtoolset.cor
 if exist "%_NUGET_CACHE%\wixtoolset.core.burn" rd /s/q "%_NUGET_CACHE%\wixtoolset.core.burn"
 if exist "%_NUGET_CACHE%\wixtoolset.core.extensioncache" rd /s/q "%_NUGET_CACHE%\wixtoolset.core.extensioncache"
 if exist "%_NUGET_CACHE%\wixtoolset.core.native" rd /s/q "%_NUGET_CACHE%\wixtoolset.core.native"
-if exist "%_NUGET_CACHE%\wixtoolset.core.testpackage" rd /s/q "%_NUGET_CACHE%\wixtoolset.core.testpackage"
 if exist "%_NUGET_CACHE%\wixtoolset.core.windowsinstaller" rd /s/q "%_NUGET_CACHE%\wixtoolset.core.windowsinstaller"
 if exist "%_NUGET_CACHE%\wixtoolset.data" rd /s/q "%_NUGET_CACHE%\wixtoolset.data"
 if exist "%_NUGET_CACHE%\wixtoolset.dependency.wixext" rd /s/q "%_NUGET_CACHE%\wixtoolset.dependency.wixext"
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs b/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
index 63b9b4a8..329722a4 100644
--- a/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/BalExtensionFixture.cs
@@ -6,9 +6,9 @@ namespace WixToolsetTest.Bal
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
     using WixToolset.Bal;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class BalExtensionFixture
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/InternalUIBAFixture.cs b/src/ext/Bal/test/WixToolsetTest.Bal/InternalUIBAFixture.cs
index dba78da4..b7609d19 100644
--- a/src/ext/Bal/test/WixToolsetTest.Bal/InternalUIBAFixture.cs
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/InternalUIBAFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.Bal
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class InternalUIBAFixture
diff --git a/src/ext/Bal/test/WixToolsetTest.Bal/WixToolsetTest.Bal.csproj b/src/ext/Bal/test/WixToolsetTest.Bal/WixToolsetTest.Bal.csproj
index 0022fc7e..644fb625 100644
--- a/src/ext/Bal/test/WixToolsetTest.Bal/WixToolsetTest.Bal.csproj
+++ b/src/ext/Bal/test/WixToolsetTest.Bal/WixToolsetTest.Bal.csproj
@@ -20,6 +20,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Bal/test/WixToolsetTest.Dnc.HostGenerator/WixToolsetTest.Dnc.HostGenerator.csproj b/src/ext/Bal/test/WixToolsetTest.Dnc.HostGenerator/WixToolsetTest.Dnc.HostGenerator.csproj
index 45c76232..1cbf702d 100644
--- a/src/ext/Bal/test/WixToolsetTest.Dnc.HostGenerator/WixToolsetTest.Dnc.HostGenerator.csproj
+++ b/src/ext/Bal/test/WixToolsetTest.Dnc.HostGenerator/WixToolsetTest.Dnc.HostGenerator.csproj
@@ -12,7 +12,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
     <PackageReference Include="WixToolset.Mba.Core" />
   </ItemGroup>
 
diff --git a/src/ext/Bal/test/WixToolsetTest.ManagedHost/DncHostFixture.cs b/src/ext/Bal/test/WixToolsetTest.ManagedHost/DncHostFixture.cs
index 02059faa..fe644d2d 100644
--- a/src/ext/Bal/test/WixToolsetTest.ManagedHost/DncHostFixture.cs
+++ b/src/ext/Bal/test/WixToolsetTest.ManagedHost/DncHostFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.ManagedHost
 {
     using System;
-    using WixBuildTools.TestSupport;
-    using WixBuildTools.TestSupport.XunitExtensions;
+    using WixInternal.TestSupport;
+    using WixInternal.TestSupport.XunitExtensions;
     using Xunit;
 
     public class DncHostFixture
diff --git a/src/ext/Bal/test/WixToolsetTest.ManagedHost/MbaHostFixture.cs b/src/ext/Bal/test/WixToolsetTest.ManagedHost/MbaHostFixture.cs
index b4ebe1c6..6f7709b5 100644
--- a/src/ext/Bal/test/WixToolsetTest.ManagedHost/MbaHostFixture.cs
+++ b/src/ext/Bal/test/WixToolsetTest.ManagedHost/MbaHostFixture.cs
@@ -2,7 +2,7 @@
 
 namespace WixToolsetTest.ManagedHost
 {
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class MbaHostFixture
diff --git a/src/ext/Bal/test/WixToolsetTest.ManagedHost/TestEngine.cs b/src/ext/Bal/test/WixToolsetTest.ManagedHost/TestEngine.cs
index 0ca2b40f..8be62e92 100644
--- a/src/ext/Bal/test/WixToolsetTest.ManagedHost/TestEngine.cs
+++ b/src/ext/Bal/test/WixToolsetTest.ManagedHost/TestEngine.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.ManagedHost
     using System.Collections.Generic;
     using System.Diagnostics;
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
 
     public class TestEngine
     {
diff --git a/src/ext/Bal/test/WixToolsetTest.ManagedHost/WixToolsetTest.ManagedHost.csproj b/src/ext/Bal/test/WixToolsetTest.ManagedHost/WixToolsetTest.ManagedHost.csproj
index e06c0440..16a05fec 100644
--- a/src/ext/Bal/test/WixToolsetTest.ManagedHost/WixToolsetTest.ManagedHost.csproj
+++ b/src/ext/Bal/test/WixToolsetTest.ManagedHost/WixToolsetTest.ManagedHost.csproj
@@ -12,6 +12,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/ComPlus/test/WixToolsetTest.ComPlus/ComPlusExtensionFixture.cs b/src/ext/ComPlus/test/WixToolsetTest.ComPlus/ComPlusExtensionFixture.cs
index d0b8daba..17c5eb0f 100644
--- a/src/ext/ComPlus/test/WixToolsetTest.ComPlus/ComPlusExtensionFixture.cs
+++ b/src/ext/ComPlus/test/WixToolsetTest.ComPlus/ComPlusExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.ComPlus
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.ComPlus;
     using Xunit;
 
diff --git a/src/ext/ComPlus/test/WixToolsetTest.ComPlus/WixToolsetTest.ComPlus.csproj b/src/ext/ComPlus/test/WixToolsetTest.ComPlus/WixToolsetTest.ComPlus.csproj
index 08008025..a9e9dbef 100644
--- a/src/ext/ComPlus/test/WixToolsetTest.ComPlus/WixToolsetTest.ComPlus.csproj
+++ b/src/ext/ComPlus/test/WixToolsetTest.ComPlus/WixToolsetTest.ComPlus.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Dependency/test/WixToolsetTest.Dependency/DependencyExtensionFixture.cs b/src/ext/Dependency/test/WixToolsetTest.Dependency/DependencyExtensionFixture.cs
index 9e837cff..6190a4e0 100644
--- a/src/ext/Dependency/test/WixToolsetTest.Dependency/DependencyExtensionFixture.cs
+++ b/src/ext/Dependency/test/WixToolsetTest.Dependency/DependencyExtensionFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.Dependency
 {
     using System.Linq;
     using System.Text.RegularExpressions;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Dependency;
     using Xunit;
 
diff --git a/src/ext/Dependency/test/WixToolsetTest.Dependency/WixToolsetTest.Dependency.csproj b/src/ext/Dependency/test/WixToolsetTest.Dependency/WixToolsetTest.Dependency.csproj
index ac4624b1..70b56f45 100644
--- a/src/ext/Dependency/test/WixToolsetTest.Dependency/WixToolsetTest.Dependency.csproj
+++ b/src/ext/Dependency/test/WixToolsetTest.Dependency/WixToolsetTest.Dependency.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/DifxApp/test/WixToolsetTest.DifxApp/DifxAppExtensionFixture.cs b/src/ext/DifxApp/test/WixToolsetTest.DifxApp/DifxAppExtensionFixture.cs
index d8f1c9ea..7bdd039b 100644
--- a/src/ext/DifxApp/test/WixToolsetTest.DifxApp/DifxAppExtensionFixture.cs
+++ b/src/ext/DifxApp/test/WixToolsetTest.DifxApp/DifxAppExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.DifxApp
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.DifxApp;
     using Xunit;
 
diff --git a/src/ext/DifxApp/test/WixToolsetTest.DifxApp/WixToolsetTest.DifxApp.csproj b/src/ext/DifxApp/test/WixToolsetTest.DifxApp/WixToolsetTest.DifxApp.csproj
index 47329768..d7176efa 100644
--- a/src/ext/DifxApp/test/WixToolsetTest.DifxApp/WixToolsetTest.DifxApp.csproj
+++ b/src/ext/DifxApp/test/WixToolsetTest.DifxApp/WixToolsetTest.DifxApp.csproj
@@ -19,6 +19,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/DirectX/test/WixToolsetTest.DirectX/DirectXExtensionFixture.cs b/src/ext/DirectX/test/WixToolsetTest.DirectX/DirectXExtensionFixture.cs
index f936cdfe..64013ca6 100644
--- a/src/ext/DirectX/test/WixToolsetTest.DirectX/DirectXExtensionFixture.cs
+++ b/src/ext/DirectX/test/WixToolsetTest.DirectX/DirectXExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.DirectX
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.DirectX;
     using Xunit;
 
diff --git a/src/ext/DirectX/test/WixToolsetTest.DirectX/WixToolsetTest.DirectX.csproj b/src/ext/DirectX/test/WixToolsetTest.DirectX/WixToolsetTest.DirectX.csproj
index dd8b9695..31a35320 100644
--- a/src/ext/DirectX/test/WixToolsetTest.DirectX/WixToolsetTest.DirectX.csproj
+++ b/src/ext/DirectX/test/WixToolsetTest.DirectX/WixToolsetTest.DirectX.csproj
@@ -19,6 +19,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Firewall/test/WixToolsetTest.Firewall/FirewallExtensionFixture.cs b/src/ext/Firewall/test/WixToolsetTest.Firewall/FirewallExtensionFixture.cs
index f7df46e6..c2c2bbc3 100644
--- a/src/ext/Firewall/test/WixToolsetTest.Firewall/FirewallExtensionFixture.cs
+++ b/src/ext/Firewall/test/WixToolsetTest.Firewall/FirewallExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.Firewall
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Firewall;
     using Xunit;
 
diff --git a/src/ext/Firewall/test/WixToolsetTest.Firewall/WixToolsetTest.Firewall.csproj b/src/ext/Firewall/test/WixToolsetTest.Firewall/WixToolsetTest.Firewall.csproj
index 03270860..e46020a6 100644
--- a/src/ext/Firewall/test/WixToolsetTest.Firewall/WixToolsetTest.Firewall.csproj
+++ b/src/ext/Firewall/test/WixToolsetTest.Firewall/WixToolsetTest.Firewall.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Http/test/WixToolsetTest.Http/HttpExtensionFixture.cs b/src/ext/Http/test/WixToolsetTest.Http/HttpExtensionFixture.cs
index 40b49327..14b40bc8 100644
--- a/src/ext/Http/test/WixToolsetTest.Http/HttpExtensionFixture.cs
+++ b/src/ext/Http/test/WixToolsetTest.Http/HttpExtensionFixture.cs
@@ -2,8 +2,8 @@
 
 namespace WixToolsetTest.Http
 {
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Http;
     using Xunit;
 
diff --git a/src/ext/Http/test/WixToolsetTest.Http/WixToolsetTest.Http.csproj b/src/ext/Http/test/WixToolsetTest.Http/WixToolsetTest.Http.csproj
index df955ca3..b23ef481 100644
--- a/src/ext/Http/test/WixToolsetTest.Http/WixToolsetTest.Http.csproj
+++ b/src/ext/Http/test/WixToolsetTest.Http/WixToolsetTest.Http.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Iis/test/WixToolsetTest.Iis/IisExtensionFixture.cs b/src/ext/Iis/test/WixToolsetTest.Iis/IisExtensionFixture.cs
index 541426a8..4684a821 100644
--- a/src/ext/Iis/test/WixToolsetTest.Iis/IisExtensionFixture.cs
+++ b/src/ext/Iis/test/WixToolsetTest.Iis/IisExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.Iis
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Iis;
     using Xunit;
 
diff --git a/src/ext/Iis/test/WixToolsetTest.Iis/WixToolsetTest.Iis.csproj b/src/ext/Iis/test/WixToolsetTest.Iis/WixToolsetTest.Iis.csproj
index d6a60a38..a39e5b0b 100644
--- a/src/ext/Iis/test/WixToolsetTest.Iis/WixToolsetTest.Iis.csproj
+++ b/src/ext/Iis/test/WixToolsetTest.Iis/WixToolsetTest.Iis.csproj
@@ -19,6 +19,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Msmq/test/WixToolsetTest.Msmq/MsmqExtensionFixture.cs b/src/ext/Msmq/test/WixToolsetTest.Msmq/MsmqExtensionFixture.cs
index c9d40d10..674d6a66 100644
--- a/src/ext/Msmq/test/WixToolsetTest.Msmq/MsmqExtensionFixture.cs
+++ b/src/ext/Msmq/test/WixToolsetTest.Msmq/MsmqExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.Msmq
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Msmq;
     using Xunit;
 
diff --git a/src/ext/Msmq/test/WixToolsetTest.Msmq/WixToolsetTest.Msmq.csproj b/src/ext/Msmq/test/WixToolsetTest.Msmq/WixToolsetTest.Msmq.csproj
index 5e4a5ca9..e7b6f21e 100644
--- a/src/ext/Msmq/test/WixToolsetTest.Msmq/WixToolsetTest.Msmq.csproj
+++ b/src/ext/Msmq/test/WixToolsetTest.Msmq/WixToolsetTest.Msmq.csproj
@@ -19,6 +19,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/NetFx/test/WixToolsetTest.Netfx/NetfxExtensionFixture.cs b/src/ext/NetFx/test/WixToolsetTest.Netfx/NetfxExtensionFixture.cs
index a03d47d6..dea42bd5 100644
--- a/src/ext/NetFx/test/WixToolsetTest.Netfx/NetfxExtensionFixture.cs
+++ b/src/ext/NetFx/test/WixToolsetTest.Netfx/NetfxExtensionFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.Netfx
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Netfx;
     using Xunit;
 
diff --git a/src/ext/NetFx/test/WixToolsetTest.Netfx/WixToolsetTest.Netfx.csproj b/src/ext/NetFx/test/WixToolsetTest.Netfx/WixToolsetTest.Netfx.csproj
index 8b13d357..4e509cce 100644
--- a/src/ext/NetFx/test/WixToolsetTest.Netfx/WixToolsetTest.Netfx.csproj
+++ b/src/ext/NetFx/test/WixToolsetTest.Netfx/WixToolsetTest.Netfx.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/PowerShell/test/WixToolsetTest.PowerShell/PowerShellExtensionFixture.cs b/src/ext/PowerShell/test/WixToolsetTest.PowerShell/PowerShellExtensionFixture.cs
index b2f27ecf..eafda99f 100644
--- a/src/ext/PowerShell/test/WixToolsetTest.PowerShell/PowerShellExtensionFixture.cs
+++ b/src/ext/PowerShell/test/WixToolsetTest.PowerShell/PowerShellExtensionFixture.cs
@@ -2,8 +2,8 @@
 
 namespace WixToolsetTest.PowerShell
 {
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.PowerShell;
     using Xunit;
 
diff --git a/src/ext/PowerShell/test/WixToolsetTest.PowerShell/WixToolsetTest.Powershell.csproj b/src/ext/PowerShell/test/WixToolsetTest.PowerShell/WixToolsetTest.Powershell.csproj
index 84241a14..347ca1ed 100644
--- a/src/ext/PowerShell/test/WixToolsetTest.PowerShell/WixToolsetTest.Powershell.csproj
+++ b/src/ext/PowerShell/test/WixToolsetTest.PowerShell/WixToolsetTest.Powershell.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Sql/test/WixToolsetTest.Sql/SqlExtensionFixture.cs b/src/ext/Sql/test/WixToolsetTest.Sql/SqlExtensionFixture.cs
index aa9d7a1f..5576576d 100644
--- a/src/ext/Sql/test/WixToolsetTest.Sql/SqlExtensionFixture.cs
+++ b/src/ext/Sql/test/WixToolsetTest.Sql/SqlExtensionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.Sql
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Sql;
     using Xunit;
 
diff --git a/src/ext/Sql/test/WixToolsetTest.Sql/WixToolsetTest.Sql.csproj b/src/ext/Sql/test/WixToolsetTest.Sql/WixToolsetTest.Sql.csproj
index de502438..6c848683 100644
--- a/src/ext/Sql/test/WixToolsetTest.Sql/WixToolsetTest.Sql.csproj
+++ b/src/ext/Sql/test/WixToolsetTest.Sql/WixToolsetTest.Sql.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs b/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
index 9c0e2ed6..4fd203c5 100644
--- a/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
+++ b/src/ext/UI/test/WixToolsetTest.UI/UIExtensionFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.UI
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data.WindowsInstaller;
     using WixToolset.UI;
     using Xunit;
diff --git a/src/ext/UI/test/WixToolsetTest.UI/WixToolsetTest.UI.csproj b/src/ext/UI/test/WixToolsetTest.UI/WixToolsetTest.UI.csproj
index 22366c79..675f14f8 100644
--- a/src/ext/UI/test/WixToolsetTest.UI/WixToolsetTest.UI.csproj
+++ b/src/ext/UI/test/WixToolsetTest.UI/WixToolsetTest.UI.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/Util/test/WixToolsetTest.Util/UtilExtensionFixture.cs b/src/ext/Util/test/WixToolsetTest.Util/UtilExtensionFixture.cs
index 3da5f671..18bb2c7d 100644
--- a/src/ext/Util/test/WixToolsetTest.Util/UtilExtensionFixture.cs
+++ b/src/ext/Util/test/WixToolsetTest.Util/UtilExtensionFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.Util
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Util;
     using Xunit;
 
diff --git a/src/ext/Util/test/WixToolsetTest.Util/WixToolsetTest.Util.csproj b/src/ext/Util/test/WixToolsetTest.Util/WixToolsetTest.Util.csproj
index 2cf3c02a..16d0e138 100644
--- a/src/ext/Util/test/WixToolsetTest.Util/WixToolsetTest.Util.csproj
+++ b/src/ext/Util/test/WixToolsetTest.Util/WixToolsetTest.Util.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/VisualStudioExtensionFixture.cs b/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/VisualStudioExtensionFixture.cs
index dc76e8fb..fdfd2e0e 100644
--- a/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/VisualStudioExtensionFixture.cs
+++ b/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/VisualStudioExtensionFixture.cs
@@ -2,8 +2,8 @@
 
 namespace WixToolsetTest.VisualStudio
 {
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.VisualStudio;
     using Xunit;
 
diff --git a/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/WixToolsetTest.VisualStudio.csproj b/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/WixToolsetTest.VisualStudio.csproj
index dffbb462..2b0a7c1c 100644
--- a/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/WixToolsetTest.VisualStudio.csproj
+++ b/src/ext/VisualStudio/test/WixToolsetTest.VisualStudio/WixToolsetTest.VisualStudio.csproj
@@ -16,6 +16,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/internal/SetBuildNumber/Directory.Packages.props.pp b/src/internal/SetBuildNumber/Directory.Packages.props.pp
index f59c9742..a14cf55a 100644
--- a/src/internal/SetBuildNumber/Directory.Packages.props.pp
+++ b/src/internal/SetBuildNumber/Directory.Packages.props.pp
@@ -6,9 +6,9 @@
     <PackageVersion Include="WixToolset.Dtf.Resources" Version="{packageversion}" />
     <PackageVersion Include="WixToolset.Dtf.WindowsInstaller" Version="{packageversion}" />
 
-    <PackageVersion Include="WixBuildTools.TestSupport" Version="{packageversion}" />
-    <PackageVersion Include="WixBuildTools.TestSupport.Native" Version="{packageversion}" />
-    <PackageVersion Include="WixToolset.BaseBuildTasks.Sources" Version="{packageversion}" />
+    <PackageVersion Include="WixInternal.TestSupport" Version="{packageversion}" />
+    <PackageVersion Include="WixInternal.TestSupport.Native" Version="{packageversion}" />
+    <PackageVersion Include="WixInternal.BaseBuildTasks.Sources" Version="{packageversion}" />
 
     <PackageVersion Include="WixToolset.DUtil" Version="{packageversion}" />
     <PackageVersion Include="WixToolset.WcaUtil" Version="{packageversion}" />
@@ -28,7 +28,7 @@
     <PackageVersion Include="WixToolset.Core" Version="{packageversion}" />
     <PackageVersion Include="WixToolset.Core.Burn" Version="{packageversion}" />
     <PackageVersion Include="WixToolset.Core.WindowsInstaller" Version="{packageversion}" />
-    <PackageVersion Include="WixToolset.Core.TestPackage" Version="{packageversion}" />
+    <PackageVersion Include="WixInternal.Core.TestPackage" Version="{packageversion}" />
 
     <PackageVersion Include="WixToolset.Heat" Version="{packageversion}" />
 
@@ -83,7 +83,7 @@
     <PackageVersion Include="Microsoft.Build.Tasks.Core" Version="15.7.179" />
   </ItemGroup>
 
-  <!-- Keep the following versions in sync with internal\WixBuildTools.TestSupport.Native\packages.config -->
+  <!-- Keep the following versions in sync with internal\WixInternal.TestSupport.Native\packages.config -->
   <ItemGroup>
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="1.1.1" />
     <PackageVersion Include="GitInfo" Version="2.2.0" />
diff --git a/src/internal/WixToolset.BaseBuildTasks.Sources/BaseToolsetTask.cs b/src/internal/WixInternal.BaseBuildTasks.Sources/BaseToolsetTask.cs
index d9e3b5e8..d9e3b5e8 100644
--- a/src/internal/WixToolset.BaseBuildTasks.Sources/BaseToolsetTask.cs
+++ b/src/internal/WixInternal.BaseBuildTasks.Sources/BaseToolsetTask.cs
diff --git a/src/internal/WixToolset.BaseBuildTasks.Sources/WixCommandLineBuilder.cs b/src/internal/WixInternal.BaseBuildTasks.Sources/WixCommandLineBuilder.cs
index d950bca9..d950bca9 100644
--- a/src/internal/WixToolset.BaseBuildTasks.Sources/WixCommandLineBuilder.cs
+++ b/src/internal/WixInternal.BaseBuildTasks.Sources/WixCommandLineBuilder.cs
diff --git a/src/internal/WixToolset.BaseBuildTasks.Sources/WixToolset.BaseBuildTasks.Sources.csproj b/src/internal/WixInternal.BaseBuildTasks.Sources/WixInternal.BaseBuildTasks.Sources.csproj
index 6ae5165e..6ae5165e 100644
--- a/src/internal/WixToolset.BaseBuildTasks.Sources/WixToolset.BaseBuildTasks.Sources.csproj
+++ b/src/internal/WixInternal.BaseBuildTasks.Sources/WixInternal.BaseBuildTasks.Sources.csproj
diff --git a/src/internal/WixBuildTools.TestSupport.Native/AssemblyInfo.cpp b/src/internal/WixInternal.TestSupport.Native/AssemblyInfo.cpp
index 23a48993..e1c47dfa 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/AssemblyInfo.cpp
+++ b/src/internal/WixInternal.TestSupport.Native/AssemblyInfo.cpp
@@ -11,7 +11,7 @@ using namespace System::Runtime::InteropServices;
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
 //
-[assembly: AssemblyTitleAttribute("WixBuildTools.TestSupport.Native")];
+[assembly: AssemblyTitleAttribute("WixInternal.TestSupport.Native")];
 [assembly: AssemblyDescriptionAttribute("")];
 [assembly: AssemblyCultureAttribute("")];
 [assembly: ComVisible(false)];
diff --git a/src/internal/WixBuildTools.TestSupport.Native/NativeAssert.h b/src/internal/WixInternal.TestSupport.Native/NativeAssert.h
index b0206b14..9ca04fea 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/NativeAssert.h
+++ b/src/internal/WixInternal.TestSupport.Native/NativeAssert.h
@@ -2,7 +2,7 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
 
-namespace WixBuildTools {
+namespace WixInternal {
 namespace TestSupport {
 
     using namespace System;
diff --git a/src/internal/WixBuildTools.TestSupport.Native/WixBuildTools.TestSupport.Native.vcxproj b/src/internal/WixInternal.TestSupport.Native/WixInternal.TestSupport.Native.vcxproj
index 47d79745..554347b8 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/WixBuildTools.TestSupport.Native.vcxproj
+++ b/src/internal/WixInternal.TestSupport.Native/WixInternal.TestSupport.Native.vcxproj
@@ -2,7 +2,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="build\WixBuildTools.TestSupport.Native.props" />
+  <Import Project="build\WixInternal.TestSupport.Native.props" />
 
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -26,12 +26,12 @@
   <PropertyGroup Label="Globals">
     <ProjectTypes>{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}</ProjectTypes>
     <ProjectGuid>{95BABD97-FBDB-453A-AF8A-FA031A07B599}</ProjectGuid>
-    <RootNamespace>WixBuildTools::TestSupport</RootNamespace>
+    <RootNamespace>WixInternal::TestSupport</RootNamespace>
     <Keyword>ManagedCProj</Keyword>
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <CharacterSet>Unicode</CharacterSet>
     <CLRSupport>true</CLRSupport>
-    <Description>WixBuildTools C++/CLI Test Support</Description>
+    <Description>WixInternal C++/CLI Test Support</Description>
     <SignOutput>false</SignOutput>
     <IsWixTestSupportProject>true</IsWixTestSupportProject>
   </PropertyGroup>
@@ -63,12 +63,12 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\WixBuildTools.TestSupport\WixBuildTools.TestSupport.csproj">
+    <ProjectReference Include="..\WixInternal.TestSupport\WixInternal.TestSupport.csproj">
       <Project>{6C57EF2C-979A-4106-A9E5-FE342810619A}</Project>
     </ProjectReference>
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <Import Project="build\WixBuildTools.TestSupport.Native.targets" />
+  <Import Project="build\WixInternal.TestSupport.Native.targets" />
   <Target Name="Pack" DependsOnTargets="Build" />
 </Project>
diff --git a/src/internal/WixBuildTools.TestSupport.Native/WixBuildTools.TestSupport.Native.vcxproj.filters b/src/internal/WixInternal.TestSupport.Native/WixInternal.TestSupport.Native.vcxproj.filters
index 34c1380f..34c1380f 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/WixBuildTools.TestSupport.Native.vcxproj.filters
+++ b/src/internal/WixInternal.TestSupport.Native/WixInternal.TestSupport.Native.vcxproj.filters
diff --git a/src/internal/WixBuildTools.TestSupport.Native/build/WixBuildTools.TestSupport.Native.props b/src/internal/WixInternal.TestSupport.Native/build/WixInternal.TestSupport.Native.props
index d9d9dab4..d9d9dab4 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/build/WixBuildTools.TestSupport.Native.props
+++ b/src/internal/WixInternal.TestSupport.Native/build/WixInternal.TestSupport.Native.props
diff --git a/src/internal/WixBuildTools.TestSupport.Native/build/WixBuildTools.TestSupport.Native.targets b/src/internal/WixInternal.TestSupport.Native/build/WixInternal.TestSupport.Native.targets
index 3d28ed57..6525e65a 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/build/WixBuildTools.TestSupport.Native.targets
+++ b/src/internal/WixInternal.TestSupport.Native/build/WixInternal.TestSupport.Native.targets
@@ -7,13 +7,13 @@
     <Reference Include="System.Core" />
   </ItemGroup>
 
-  <!-- Include these references only when not referenced by the WixBuildTools.TestSupport.Native.vcxproj -->
+  <!-- Include these references only when not referenced by the WixInternal.TestSupport.Native.vcxproj -->
   <ItemGroup Condition="'$(MSBuildProjectName)'!='$(MSBuildThisFileName)'">
-    <Reference Include="WixBuildTools.TestSupport">
-      <HintPath>$(RootBuildFolder)internal\$(Configuration)\$(PlatformTarget)\WixBuildTools.TestSupport.dll</HintPath>
+    <Reference Include="WixInternal.TestSupport">
+      <HintPath>$(RootBuildFolder)internal\$(Configuration)\$(PlatformTarget)\WixInternal.TestSupport.dll</HintPath>
     </Reference>
-    <Reference Include="WixBuildTools.TestSupport.Native">
-      <HintPath>$(RootBuildFolder)internal\$(Configuration)\$(PlatformTarget)\WixBuildTools.TestSupport.Native.dll</HintPath>
+    <Reference Include="WixInternal.TestSupport.Native">
+      <HintPath>$(RootBuildFolder)internal\$(Configuration)\$(PlatformTarget)\WixInternal.TestSupport.Native.dll</HintPath>
     </Reference>
   </ItemGroup>
 
diff --git a/src/internal/WixBuildTools.TestSupport.Native/packages.config b/src/internal/WixInternal.TestSupport.Native/packages.config
index 060bff6b..ef2b43c8 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/packages.config
+++ b/src/internal/WixInternal.TestSupport.Native/packages.config
@@ -3,7 +3,7 @@
 
 <packages>
   <!--
-    Update build\WixBuildTools.TestSupport.native.props and build\WixBuildTools.TestSupport.native.targets
+    Update build\WixInternal.TestSupport.Native.props and build\WixInternal.TestSupport.Native.targets
     when any of these versions are updated.
   -->
   <package id="GitInfo" version="2.2.0" />
diff --git a/src/internal/WixBuildTools.TestSupport.Native/precomp.cpp b/src/internal/WixInternal.TestSupport.Native/precomp.cpp
index 37664a1c..37664a1c 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/precomp.cpp
+++ b/src/internal/WixInternal.TestSupport.Native/precomp.cpp
diff --git a/src/internal/WixBuildTools.TestSupport.Native/precomp.h b/src/internal/WixInternal.TestSupport.Native/precomp.h
index f54b55be..f54b55be 100644
--- a/src/internal/WixBuildTools.TestSupport.Native/precomp.h
+++ b/src/internal/WixInternal.TestSupport.Native/precomp.h
diff --git a/src/internal/WixBuildTools.TestSupport/Builder.cs b/src/internal/WixInternal.TestSupport/Builder.cs
index 31df0084..fa6e0064 100644
--- a/src/internal/WixBuildTools.TestSupport/Builder.cs
+++ b/src/internal/WixInternal.TestSupport/Builder.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/internal/WixBuildTools.TestSupport/DisposableFileSystem.cs b/src/internal/WixInternal.TestSupport/DisposableFileSystem.cs
index f096db72..b03bbaa4 100644
--- a/src/internal/WixBuildTools.TestSupport/DisposableFileSystem.cs
+++ b/src/internal/WixInternal.TestSupport/DisposableFileSystem.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/internal/WixBuildTools.TestSupport/DotnetRunner.cs b/src/internal/WixInternal.TestSupport/DotnetRunner.cs
index 82391178..befd8952 100644
--- a/src/internal/WixBuildTools.TestSupport/DotnetRunner.cs
+++ b/src/internal/WixInternal.TestSupport/DotnetRunner.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/internal/WixBuildTools.TestSupport/ExternalExecutable.cs b/src/internal/WixInternal.TestSupport/ExternalExecutable.cs
index 4a932645..e0345dfb 100644
--- a/src/internal/WixBuildTools.TestSupport/ExternalExecutable.cs
+++ b/src/internal/WixInternal.TestSupport/ExternalExecutable.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Concurrent;
diff --git a/src/internal/WixBuildTools.TestSupport/ExternalExecutableResult.cs b/src/internal/WixInternal.TestSupport/ExternalExecutableResult.cs
index 950ee4bd..a142e07a 100644
--- a/src/internal/WixBuildTools.TestSupport/ExternalExecutableResult.cs
+++ b/src/internal/WixInternal.TestSupport/ExternalExecutableResult.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System.Diagnostics;
 
diff --git a/src/internal/WixBuildTools.TestSupport/FakeBuildEngine.cs b/src/internal/WixInternal.TestSupport/FakeBuildEngine.cs
index 20545970..c1f07708 100644
--- a/src/internal/WixBuildTools.TestSupport/FakeBuildEngine.cs
+++ b/src/internal/WixInternal.TestSupport/FakeBuildEngine.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System.Collections;
     using System.Text;
diff --git a/src/internal/WixBuildTools.TestSupport/MsbuildRunner.cs b/src/internal/WixInternal.TestSupport/MsbuildRunner.cs
index ac7caf0e..2cbf5e91 100644
--- a/src/internal/WixBuildTools.TestSupport/MsbuildRunner.cs
+++ b/src/internal/WixInternal.TestSupport/MsbuildRunner.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/internal/WixBuildTools.TestSupport/MsbuildRunnerResult.cs b/src/internal/WixInternal.TestSupport/MsbuildRunnerResult.cs
index fb61122d..b85acb16 100644
--- a/src/internal/WixBuildTools.TestSupport/MsbuildRunnerResult.cs
+++ b/src/internal/WixInternal.TestSupport/MsbuildRunnerResult.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using Xunit;
diff --git a/src/internal/WixBuildTools.TestSupport/MsbuildUtilities.cs b/src/internal/WixInternal.TestSupport/MsbuildUtilities.cs
index 3271cc20..5560f993 100644
--- a/src/internal/WixBuildTools.TestSupport/MsbuildUtilities.cs
+++ b/src/internal/WixInternal.TestSupport/MsbuildUtilities.cs
@@ -6,7 +6,7 @@ namespace WixToolsetTest.Sdk
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
 
     public enum BuildSystem
     {
diff --git a/src/internal/WixBuildTools.TestSupport/Pushd.cs b/src/internal/WixInternal.TestSupport/Pushd.cs
index d0545215..43737382 100644
--- a/src/internal/WixBuildTools.TestSupport/Pushd.cs
+++ b/src/internal/WixInternal.TestSupport/Pushd.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.IO;
diff --git a/src/internal/WixBuildTools.TestSupport/Query.cs b/src/internal/WixInternal.TestSupport/Query.cs
index 101a8890..38f5df64 100644
--- a/src/internal/WixBuildTools.TestSupport/Query.cs
+++ b/src/internal/WixInternal.TestSupport/Query.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/internal/WixBuildTools.TestSupport/RobocopyRunner.cs b/src/internal/WixInternal.TestSupport/RobocopyRunner.cs
index 49d53351..d93fbaa0 100644
--- a/src/internal/WixBuildTools.TestSupport/RobocopyRunner.cs
+++ b/src/internal/WixInternal.TestSupport/RobocopyRunner.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     public class RobocopyRunner : ExternalExecutable
     {
diff --git a/src/internal/WixBuildTools.TestSupport/TestData.cs b/src/internal/WixInternal.TestSupport/TestData.cs
index fc1ae4cc..05691e8c 100644
--- a/src/internal/WixBuildTools.TestSupport/TestData.cs
+++ b/src/internal/WixInternal.TestSupport/TestData.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.IO;
diff --git a/src/internal/WixBuildTools.TestSupport/TestDataFolderFileSystem.cs b/src/internal/WixInternal.TestSupport/TestDataFolderFileSystem.cs
index 15b7631d..38b05101 100644
--- a/src/internal/WixBuildTools.TestSupport/TestDataFolderFileSystem.cs
+++ b/src/internal/WixInternal.TestSupport/TestDataFolderFileSystem.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
 
diff --git a/src/internal/WixBuildTools.TestSupport/VswhereRunner.cs b/src/internal/WixInternal.TestSupport/VswhereRunner.cs
index 0197e125..f7361423 100644
--- a/src/internal/WixBuildTools.TestSupport/VswhereRunner.cs
+++ b/src/internal/WixInternal.TestSupport/VswhereRunner.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.IO;
diff --git a/src/internal/WixBuildTools.TestSupport/WixBuildTools.TestSupport.csproj b/src/internal/WixInternal.TestSupport/WixInternal.TestSupport.csproj
index 4e1c3c26..4e1c3c26 100644
--- a/src/internal/WixBuildTools.TestSupport/WixBuildTools.TestSupport.csproj
+++ b/src/internal/WixInternal.TestSupport/WixInternal.TestSupport.csproj
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkipTestException.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkipTestException.cs
index bd7d23f9..6ef30829 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkipTestException.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkipTestException.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System;
 
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactAttribute.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactAttribute.cs
index 4974d489..ba4678c8 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactAttribute.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactAttribute.cs
@@ -1,12 +1,12 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using Xunit;
     using Xunit.Sdk;
 
     // https://github.com/xunit/samples.xunit/blob/5dc1d35a63c3394a8678ac466b882576a70f56f6/DynamicSkipExample
-    [XunitTestCaseDiscoverer("WixBuildTools.TestSupport.XunitExtensions.SkippableFactDiscoverer", "WixBuildTools.TestSupport")]
+    [XunitTestCaseDiscoverer("WixInternal.TestSupport.XunitExtensions.SkippableFactDiscoverer", "WixInternal.TestSupport")]
     public class SkippableFactAttribute : FactAttribute
     {
     }
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactDiscoverer.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactDiscoverer.cs
index b692c912..d5061b04 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactDiscoverer.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactDiscoverer.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System.Collections.Generic;
     using Xunit.Abstractions;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactMessageBus.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactMessageBus.cs
index 6d01889e..dd143c93 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactMessageBus.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactMessageBus.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System.Linq;
     using Xunit.Abstractions;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactTestCase.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactTestCase.cs
index f13fec83..7a78b820 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableFactTestCase.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableFactTestCase.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System;
     using System.ComponentModel;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryAttribute.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryAttribute.cs
index e026bb59..1ed04e01 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryAttribute.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryAttribute.cs
@@ -1,11 +1,11 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using Xunit;
     using Xunit.Sdk;
 
-    [XunitTestCaseDiscoverer("WixBuildTools.TestSupport.XunitExtensions.SkippableFactDiscoverer", "WixBuildTools.TestSupport")]
+    [XunitTestCaseDiscoverer("WixInternal.TestSupport.XunitExtensions.SkippableFactDiscoverer", "WixInternal.TestSupport")]
     public class SkippableTheoryAttribute : TheoryAttribute
     {
     }
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryDiscoverer.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryDiscoverer.cs
index cf4e2b43..bf850cba 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryDiscoverer.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryDiscoverer.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System.Collections.Generic;
     using Xunit.Abstractions;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryTestCase.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryTestCase.cs
index 3299fe7e..d9b7d068 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SkippableTheoryTestCase.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SkippableTheoryTestCase.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport.XunitExtensions
+namespace WixInternal.TestSupport.XunitExtensions
 {
     using System;
     using System.ComponentModel;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SpecificReturnCodeException.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SpecificReturnCodeException.cs
index c703e90a..49be13d5 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SpecificReturnCodeException.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SpecificReturnCodeException.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using Xunit.Sdk;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SucceededException.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/SucceededException.cs
index 704fba28..d50c07ed 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/SucceededException.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/SucceededException.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using Xunit.Sdk;
diff --git a/src/internal/WixBuildTools.TestSupport/XunitExtensions/WixAssert.cs b/src/internal/WixInternal.TestSupport/XunitExtensions/WixAssert.cs
index a8513bfb..66f831a1 100644
--- a/src/internal/WixBuildTools.TestSupport/XunitExtensions/WixAssert.cs
+++ b/src/internal/WixInternal.TestSupport/XunitExtensions/WixAssert.cs
@@ -1,13 +1,13 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixBuildTools.TestSupport
+namespace WixInternal.TestSupport
 {
     using System;
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport.XunitExtensions;
+    using WixInternal.TestSupport.XunitExtensions;
     using Xunit;
     using Xunit.Sdk;
 
@@ -46,8 +46,8 @@ namespace WixBuildTools.TestSupport
 
         /// <summary>
         /// Dynamically skips the test.
-        /// Requires that the test was marked with a fact attribute derived from <see cref="WixBuildTools.TestSupport.XunitExtensions.SkippableFactAttribute" />
-        /// or <see cref="WixBuildTools.TestSupport.XunitExtensions.SkippableTheoryAttribute" />
+        /// Requires that the test was marked with a fact attribute derived from <see cref="WixInternal.TestSupport.XunitExtensions.SkippableFactAttribute" />
+        /// or <see cref="WixInternal.TestSupport.XunitExtensions.SkippableTheoryAttribute" />
         /// </summary>
         public static void Skip(string message)
         {
diff --git a/src/internal/internal.cmd b/src/internal/internal.cmd
index 32df26e9..18b7b418 100644
--- a/src/internal/internal.cmd
+++ b/src/internal/internal.cmd
@@ -31,12 +31,12 @@ msbuild internal_t.proj -p:Configuration=%_C% -nologo -warnaserror -bl:%_L%\inte
 
 :clean
 @rd /s/q "..\..\build\internal" 2> nul
-@del "..\..\build\artifacts\WixBuildTools.TestSupport.*.nupkg" 2> nul
-@del "..\..\build\artifacts\WixBuildTools.TestSupport.Native.*.nupkg" 2> nul
-@del "..\..\build\artifacts\WixToolset.BaseBuildTasks.Sources.*.nupkg" 2> nul
-@rd /s/q "%USERPROFILE%\.nuget\packages\wixbuildtools.testsupport" 2> nul
-@rd /s/q "%USERPROFILE%\.nuget\packages\wixbuildtools.testsupport.native" 2> nul
-@rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.basebuildtasks.sources" 2> nul
+@del "..\..\build\artifacts\WixInternal.TestSupport.*.nupkg" 2> nul
+@del "..\..\build\artifacts\WixInternal.TestSupport.Native.*.nupkg" 2> nul
+@del "..\..\build\artifacts\WixInternal.BaseBuildTasks.Sources.*.nupkg" 2> nul
+@rd /s/q "%USERPROFILE%\.nuget\packages\wixinternal.testsupport" 2> nul
+@rd /s/q "%USERPROFILE%\.nuget\packages\wixinternal.testsupport.native" 2> nul
+@rd /s/q "%USERPROFILE%\.nuget\packages\wixinternal.basebuildtasks.sources" 2> nul
 @exit /b
 
 :end
diff --git a/src/internal/internal.sln b/src/internal/internal.sln
index fe36efbe..e8d8db17 100644
--- a/src/internal/internal.sln
+++ b/src/internal/internal.sln
@@ -3,11 +3,11 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.3.32929.385
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixBuildTools.TestSupport", "WixBuildTools.TestSupport\WixBuildTools.TestSupport.csproj", "{8E082709-7355-41D5-AF86-6BBF9C89BDD7}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixInternal.TestSupport", "WixInternal.TestSupport\WixInternal.TestSupport.csproj", "{8E082709-7355-41D5-AF86-6BBF9C89BDD7}"
 EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "WixBuildTools.TestSupport.Native", "WixBuildTools.TestSupport.Native\WixBuildTools.TestSupport.Native.vcxproj", "{95BABD97-FBDB-453A-AF8A-FA031A07B599}"
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "WixInternal.TestSupport.Native", "WixInternal.TestSupport.Native\WixInternal.TestSupport.Native.vcxproj", "{95BABD97-FBDB-453A-AF8A-FA031A07B599}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixToolset.BaseBuildTasks.Sources", "WixToolset.BaseBuildTasks.Sources\WixToolset.BaseBuildTasks.Sources.csproj", "{6B654490-AB0D-4F94-B564-DAA80044D5A3}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixInternal.BaseBuildTasks.Sources", "WixInternal.BaseBuildTasks.Sources\WixInternal.BaseBuildTasks.Sources.csproj", "{6B654490-AB0D-4F94-B564-DAA80044D5A3}"
 EndProject
 Global
         GlobalSection(SolutionConfigurationPlatforms) = preSolution
diff --git a/src/internal/internal_t.proj b/src/internal/internal_t.proj
index fc4956d2..7dd52354 100644
--- a/src/internal/internal_t.proj
+++ b/src/internal/internal_t.proj
@@ -1,8 +1,8 @@
 <Project Sdk="Microsoft.Build.Traversal">
   <ItemGroup>
-    <ProjectReference Include="WixToolset.BaseBuildTasks.Sources\WixToolset.BaseBuildTasks.Sources.csproj" Targets="Pack" />
-    <ProjectReference Include="WixBuildTools.TestSupport\WixBuildTools.TestSupport.csproj" Targets="Pack" />
-    <ProjectReference Include="WixBuildTools.TestSupport.Native\WixBuildTools.TestSupport.Native.vcxproj" Properties="Platform=x86" />
-    <ProjectReference Include="WixBuildTools.TestSupport.Native\WixBuildTools.TestSupport.Native.vcxproj" Properties="Platform=x64" />
+    <ProjectReference Include="WixInternal.BaseBuildTasks.Sources\WixInternal.BaseBuildTasks.Sources.csproj" Targets="Pack" />
+    <ProjectReference Include="WixInternal.TestSupport\WixInternal.TestSupport.csproj" Targets="Pack" />
+    <ProjectReference Include="WixInternal.TestSupport.Native\WixInternal.TestSupport.Native.vcxproj" Properties="Platform=x86" />
+    <ProjectReference Include="WixInternal.TestSupport.Native\WixInternal.TestSupport.Native.vcxproj" Properties="Platform=x64" />
   </ItemGroup>
 </Project>
diff --git a/src/libs/dutil/test/DUtilUnitTest/AppUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/AppUtilTests.cpp
index e8c23469..ee4a80a6 100644
--- a/src/libs/dutil/test/DUtilUnitTest/AppUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/AppUtilTests.cpp
@@ -6,7 +6,7 @@ namespace DutilTests
 {
     using namespace System;
     using namespace Xunit;
-    using namespace WixBuildTools::TestSupport;
+    using namespace WixInternal::TestSupport;
 
     public ref class AppUtil
     {
diff --git a/src/libs/dutil/test/DUtilUnitTest/ApupUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/ApupUtilTests.cpp
index 30a45f5a..c2371636 100644
--- a/src/libs/dutil/test/DUtilUnitTest/ApupUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/ApupUtilTests.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/DUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/DUtilTests.cpp
index 5e2d69e1..dd17a50e 100644
--- a/src/libs/dutil/test/DUtilUnitTest/DUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/DUtilTests.cpp
@@ -4,8 +4,8 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/DUtilUnitTest.vcxproj b/src/libs/dutil/test/DUtilUnitTest/DUtilUnitTest.vcxproj
index ea66ef46..edf8ba67 100644
--- a/src/libs/dutil/test/DUtilUnitTest/DUtilUnitTest.vcxproj
+++ b/src/libs/dutil/test/DUtilUnitTest/DUtilUnitTest.vcxproj
@@ -2,7 +2,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
 
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.props" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.props" />
 
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -94,5 +94,5 @@
   </ItemGroup>
 
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
-  <Import Project="..\..\..\..\internal\WixBuildTools.TestSupport.Native\build\WixBuildTools.TestSupport.Native.targets" />
+  <Import Project="..\..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.targets" />
 </Project>
diff --git a/src/libs/dutil/test/DUtilUnitTest/DictUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/DictUtilTest.cpp
index 4b4777d7..22f71fe2 100644
--- a/src/libs/dutil/test/DUtilUnitTest/DictUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/DictUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 const DWORD numIterations = 100000;
 
diff --git a/src/libs/dutil/test/DUtilUnitTest/DirUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/DirUtilTests.cpp
index 14ed7807..3475af87 100644
--- a/src/libs/dutil/test/DUtilUnitTest/DirUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/DirUtilTests.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/EnvUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/EnvUtilTests.cpp
index 94b9ab8e..6bd78f0b 100644
--- a/src/libs/dutil/test/DUtilUnitTest/EnvUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/EnvUtilTests.cpp
@@ -5,8 +5,8 @@
 using namespace System;
 using namespace System::Collections;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/FileUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/FileUtilTest.cpp
index 522361ae..8ea045f5 100644
--- a/src/libs/dutil/test/DUtilUnitTest/FileUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/FileUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/GuidUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/GuidUtilTest.cpp
index a6e27a09..a184df68 100644
--- a/src/libs/dutil/test/DUtilUnitTest/GuidUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/GuidUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/IniUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/IniUtilTest.cpp
index 946f19c5..82a12ee8 100644
--- a/src/libs/dutil/test/DUtilUnitTest/IniUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/IniUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 typedef HRESULT (__clrcall *IniFormatParameters)(
     INI_HANDLE
diff --git a/src/libs/dutil/test/DUtilUnitTest/LocUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/LocUtilTests.cpp
index c30ae2e1..0376a340 100644
--- a/src/libs/dutil/test/DUtilUnitTest/LocUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/LocUtilTests.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/MemUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/MemUtilTest.cpp
index 520ed426..f835b3e1 100644
--- a/src/libs/dutil/test/DUtilUnitTest/MemUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/MemUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/MonUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/MonUtilTest.cpp
index 09d0aeab..d9c75bf6 100644
--- a/src/libs/dutil/test/DUtilUnitTest/MonUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/MonUtilTest.cpp
@@ -7,7 +7,7 @@ using namespace System;
 using namespace System::Collections::Generic;
 using namespace System::Runtime::InteropServices;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/PathUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/PathUtilTest.cpp
index 109c558c..381ea39a 100644
--- a/src/libs/dutil/test/DUtilUnitTest/PathUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/PathUtilTest.cpp
@@ -5,7 +5,7 @@
 using namespace System;
 using namespace System::IO;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 // from PathCch.h
 #ifndef PATHCCH_ALLOW_LONG_PATHS
diff --git a/src/libs/dutil/test/DUtilUnitTest/ProcUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/ProcUtilTest.cpp
index 8672ed38..e2cd5995 100644
--- a/src/libs/dutil/test/DUtilUnitTest/ProcUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/ProcUtilTest.cpp
@@ -5,8 +5,8 @@
 using namespace System;
 using namespace System::Security::Principal;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
-using namespace WixBuildTools::TestSupport::XunitExtensions;
+using namespace WixInternal::TestSupport;
+using namespace WixInternal::TestSupport::XunitExtensions;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/RegUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/RegUtilTest.cpp
index 7c67bedf..569cec17 100644
--- a/src/libs/dutil/test/DUtilUnitTest/RegUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/RegUtilTest.cpp
@@ -6,7 +6,7 @@ using namespace System;
 using namespace System::Collections::Generic;
 using namespace System::Runtime::InteropServices;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 LPCWSTR wzBaseRegKey = L"Software\\RegUtilTest\\";
 LPWSTR rgwzMultiValue[2] = { L"First", L"Second" };
diff --git a/src/libs/dutil/test/DUtilUnitTest/StrUtilTest.cpp b/src/libs/dutil/test/DUtilUnitTest/StrUtilTest.cpp
index 94fee280..89ed3dbb 100644
--- a/src/libs/dutil/test/DUtilUnitTest/StrUtilTest.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/StrUtilTest.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/dutil/test/DUtilUnitTest/VerUtilTests.cpp b/src/libs/dutil/test/DUtilUnitTest/VerUtilTests.cpp
index 3e414006..d0ada77f 100644
--- a/src/libs/dutil/test/DUtilUnitTest/VerUtilTests.cpp
+++ b/src/libs/dutil/test/DUtilUnitTest/VerUtilTests.cpp
@@ -4,7 +4,7 @@
 
 using namespace System;
 using namespace Xunit;
-using namespace WixBuildTools::TestSupport;
+using namespace WixInternal::TestSupport;
 
 namespace DutilTests
 {
diff --git a/src/libs/test/WixToolsetTest.Versioning/WixToolsetTest.Versioning.csproj b/src/libs/test/WixToolsetTest.Versioning/WixToolsetTest.Versioning.csproj
index 0ac65fec..79d4ef35 100644
--- a/src/libs/test/WixToolsetTest.Versioning/WixToolsetTest.Versioning.csproj
+++ b/src/libs/test/WixToolsetTest.Versioning/WixToolsetTest.Versioning.csproj
@@ -12,6 +12,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/test/burn/WixTestTools/BundleVerifier.cs b/src/test/burn/WixTestTools/BundleVerifier.cs
index 3a19ca02..b750c80c 100644
--- a/src/test/burn/WixTestTools/BundleVerifier.cs
+++ b/src/test/burn/WixTestTools/BundleVerifier.cs
@@ -7,7 +7,7 @@ namespace WixTestTools
     using System.Linq;
     using System.Text;
     using Microsoft.Win32;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/test/burn/WixTestTools/MSIExec.cs b/src/test/burn/WixTestTools/MSIExec.cs
index fb161495..98f54c56 100644
--- a/src/test/burn/WixTestTools/MSIExec.cs
+++ b/src/test/burn/WixTestTools/MSIExec.cs
@@ -5,7 +5,7 @@ namespace WixTestTools
     using System;
     using System.IO;
     using System.Text;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
 
     public class MSIExec : TestTool
     {
diff --git a/src/test/burn/WixTestTools/RuntimeFactAttribute.cs b/src/test/burn/WixTestTools/RuntimeFactAttribute.cs
index fcd19b95..f73c87a2 100644
--- a/src/test/burn/WixTestTools/RuntimeFactAttribute.cs
+++ b/src/test/burn/WixTestTools/RuntimeFactAttribute.cs
@@ -4,7 +4,7 @@ namespace WixTestTools
 {
     using System;
     using System.Security.Principal;
-    using WixBuildTools.TestSupport.XunitExtensions;
+    using WixInternal.TestSupport.XunitExtensions;
 
     public class RuntimeFactAttribute : SkippableFactAttribute
     {
diff --git a/src/test/burn/WixTestTools/TestTool.cs b/src/test/burn/WixTestTools/TestTool.cs
index 79e7004c..b6d18ac9 100644
--- a/src/test/burn/WixTestTools/TestTool.cs
+++ b/src/test/burn/WixTestTools/TestTool.cs
@@ -6,7 +6,7 @@ namespace WixTestTools
     using System.Collections.Generic;
     using System.Text;
     using System.Text.RegularExpressions;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class TestTool : ExternalExecutable
diff --git a/src/test/burn/WixTestTools/WixTestContext.cs b/src/test/burn/WixTestTools/WixTestContext.cs
index a4e666f1..a87a56fa 100644
--- a/src/test/burn/WixTestTools/WixTestContext.cs
+++ b/src/test/burn/WixTestTools/WixTestContext.cs
@@ -7,7 +7,7 @@ namespace WixTestTools
     using System.Linq;
     using System.Reflection;
     using Microsoft.Win32;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit.Abstractions;
 
     public class WixTestContext
diff --git a/src/test/burn/WixTestTools/WixTestTools.csproj b/src/test/burn/WixTestTools/WixTestTools.csproj
index 47456868..65db5a60 100644
--- a/src/test/burn/WixTestTools/WixTestTools.csproj
+++ b/src/test/burn/WixTestTools/WixTestTools.csproj
@@ -13,7 +13,7 @@
     <PackageReference Include="System.DirectoryServices" />
     <PackageReference Include="System.DirectoryServices.AccountManagement" />
     <PackageReference Include="System.Security.Principal.Windows" />
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
     <PackageReference Include="WixToolset.Data" />
     <PackageReference Include="WixToolset.Mba.Core" />
   </ItemGroup>
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/BasicFunctionalityTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/BasicFunctionalityTests.cs
index 4d915c02..8b513372 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/BasicFunctionalityTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/BasicFunctionalityTests.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.BurnE2E
 {
     using System;
     using System.IO;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixTestTools;
     using Xunit;
     using Xunit.Abstractions;
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/CacheTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/CacheTests.cs
index afc3fc10..16623ffb 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/CacheTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/CacheTests.cs
@@ -6,7 +6,7 @@ namespace WixToolsetTest.BurnE2E
     using System.Collections.Generic;
     using System.IO;
     using Microsoft.Win32;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixTestTools;
     using WixToolset.Mba.Core;
     using Xunit;
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/LayoutTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/LayoutTests.cs
index 14c3cd5d..44918304 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/LayoutTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/LayoutTests.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.BurnE2E
 {
     using System.Collections.Generic;
     using System.IO;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixTestTools;
     using Xunit;
     using Xunit.Abstractions;
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/LongPathTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/LongPathTests.cs
index b751ff75..e7732d82 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/LongPathTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/LongPathTests.cs
@@ -7,7 +7,7 @@ namespace WixToolsetTest.BurnE2E
     using System.IO;
     using System.Runtime.InteropServices;
     using Microsoft.Win32;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixTestTools;
     using WixToolset.Mba.Core;
     using Xunit;
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/Utilities/TestExeTool.cs b/src/test/burn/WixToolsetTest.BurnE2E/Utilities/TestExeTool.cs
index 07442cd3..b552a0a0 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/Utilities/TestExeTool.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/Utilities/TestExeTool.cs
@@ -3,7 +3,7 @@
 namespace WixTestTools
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
 
     public class TestExeTool : TestTool
     {
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/VariableTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/VariableTests.cs
index e7b1362f..22e94260 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/VariableTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/VariableTests.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.BurnE2E
 {
     using System.Collections.Generic;
     using System.IO;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixTestTools;
     using WixToolset.Mba.Core;
     using Xunit;
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/WixToolsetTest.BurnE2E.csproj b/src/test/burn/WixToolsetTest.BurnE2E/WixToolsetTest.BurnE2E.csproj
index 7305dcbf..a5099d9b 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/WixToolsetTest.BurnE2E.csproj
+++ b/src/test/burn/WixToolsetTest.BurnE2E/WixToolsetTest.BurnE2E.csproj
@@ -20,7 +20,7 @@
     <PackageReference Include="Microsoft.AspNetCore.Owin" />
     <PackageReference Include="Microsoft.Win32.Registry" />
     <PackageReference Include="System.Security.Principal.Windows" />
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
     <PackageReference Include="WixToolset.Data" />
     <PackageReference Include="WixToolset.Mba.Core" />
   </ItemGroup>
diff --git a/src/test/msi/WixToolsetTest.MsiE2E/WixToolsetTest.MsiE2E.csproj b/src/test/msi/WixToolsetTest.MsiE2E/WixToolsetTest.MsiE2E.csproj
index 7e479327..d64c942a 100644
--- a/src/test/msi/WixToolsetTest.MsiE2E/WixToolsetTest.MsiE2E.csproj
+++ b/src/test/msi/WixToolsetTest.MsiE2E/WixToolsetTest.MsiE2E.csproj
@@ -19,7 +19,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Win32.Registry" />
     <PackageReference Include="System.Security.Principal.Windows" />
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
     <PackageReference Include="WixToolset.Data" />
   </ItemGroup>
 </Project>
diff --git a/src/test/wix/WixE2E/WixE2E.csproj b/src/test/wix/WixE2E/WixE2E.csproj
index d85cc152..055df524 100644
--- a/src/test/wix/WixE2E/WixE2E.csproj
+++ b/src/test/wix/WixE2E/WixE2E.csproj
@@ -12,6 +12,6 @@
   </ItemGroup>
 
   <ItemGroup>
-     <PackageReference Include="WixBuildTools.TestSupport" /> 
+     <PackageReference Include="WixInternal.TestSupport" /> 
   </ItemGroup>
 </Project>
diff --git a/src/test/wix/WixE2E/WixE2EFixture.cs b/src/test/wix/WixE2E/WixE2EFixture.cs
index 5574680f..88902206 100644
--- a/src/test/wix/WixE2E/WixE2EFixture.cs
+++ b/src/test/wix/WixE2E/WixE2EFixture.cs
@@ -8,7 +8,7 @@ namespace WixE2E
     using System.Security.Cryptography;
     using System.Text;
     using System.Threading;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class WixE2EFixture
diff --git a/src/tools/WixToolset.HeatTasks/WixToolset.HeatTasks.csproj b/src/tools/WixToolset.HeatTasks/WixToolset.HeatTasks.csproj
index a8538d9e..21460810 100644
--- a/src/tools/WixToolset.HeatTasks/WixToolset.HeatTasks.csproj
+++ b/src/tools/WixToolset.HeatTasks/WixToolset.HeatTasks.csproj
@@ -12,6 +12,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Build.Tasks.Core" />
-    <PackageReference Include="WixToolset.BaseBuildTasks.Sources" />
+    <PackageReference Include="WixInternal.BaseBuildTasks.Sources" />
   </ItemGroup>
 </Project>
diff --git a/src/tools/test/WixToolsetTest.Heat/HeatFixture.cs b/src/tools/test/WixToolsetTest.Heat/HeatFixture.cs
index befcedcc..388d4dc0 100644
--- a/src/tools/test/WixToolsetTest.Heat/HeatFixture.cs
+++ b/src/tools/test/WixToolsetTest.Heat/HeatFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Heat
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class HeatFixture
diff --git a/src/tools/test/WixToolsetTest.Heat/HeatRunner.cs b/src/tools/test/WixToolsetTest.Heat/HeatRunner.cs
index c914dcac..e4004300 100644
--- a/src/tools/test/WixToolsetTest.Heat/HeatRunner.cs
+++ b/src/tools/test/WixToolsetTest.Heat/HeatRunner.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Heat
     using System.Collections.Generic;
     using System.Threading.Tasks;
     using WixToolset.Core;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Extensibility.Services;
     using WixToolset.Tools.Heat;
diff --git a/src/tools/test/WixToolsetTest.Heat/WixToolsetTest.Heat.csproj b/src/tools/test/WixToolsetTest.Heat/WixToolsetTest.Heat.csproj
index cb4deae1..fb86ecdf 100644
--- a/src/tools/test/WixToolsetTest.Heat/WixToolsetTest.Heat.csproj
+++ b/src/tools/test/WixToolsetTest.Heat/WixToolsetTest.Heat.csproj
@@ -17,6 +17,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixToolset.Core.TestPackage" />
+    <PackageReference Include="WixInternal.Core.TestPackage" />
   </ItemGroup>
 </Project>
diff --git a/src/tools/test/WixToolsetTest.HeatTasks/MsbuildHeatFixture.cs b/src/tools/test/WixToolsetTest.HeatTasks/MsbuildHeatFixture.cs
index a0a98578..1b7e1a32 100644
--- a/src/tools/test/WixToolsetTest.HeatTasks/MsbuildHeatFixture.cs
+++ b/src/tools/test/WixToolsetTest.HeatTasks/MsbuildHeatFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.Sdk
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/tools/test/WixToolsetTest.HeatTasks/WixToolsetTest.HeatTasks.csproj b/src/tools/test/WixToolsetTest.HeatTasks/WixToolsetTest.HeatTasks.csproj
index 03b7cb88..390154de 100644
--- a/src/tools/test/WixToolsetTest.HeatTasks/WixToolsetTest.HeatTasks.csproj
+++ b/src/tools/test/WixToolsetTest.HeatTasks/WixToolsetTest.HeatTasks.csproj
@@ -14,7 +14,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" /> 
-    <PackageReference Include="WixToolset.Core.TestPackage" /> 
+    <PackageReference Include="WixInternal.TestSupport" /> 
+    <PackageReference Include="WixInternal.Core.TestPackage" /> 
   </ItemGroup>
 </Project>
diff --git a/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs b/src/wix/WixInternal.Core.TestPackage/BundleExtractor.cs
index 3161c4eb..dc4005a5 100644
--- a/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs
+++ b/src/wix/WixInternal.Core.TestPackage/BundleExtractor.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/wix/WixToolset.Core.TestPackage/ExtractBAContainerResult.cs b/src/wix/WixInternal.Core.TestPackage/ExtractBAContainerResult.cs
index 5f4a5369..ab45d68e 100644
--- a/src/wix/WixToolset.Core.TestPackage/ExtractBAContainerResult.cs
+++ b/src/wix/WixInternal.Core.TestPackage/ExtractBAContainerResult.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
     using System.Collections.Generic;
     using System.IO;
diff --git a/src/wix/WixToolset.Core.TestPackage/TestMessageListener.cs b/src/wix/WixInternal.Core.TestPackage/TestMessageListener.cs
index 7040fe82..db536e2a 100644
--- a/src/wix/WixToolset.Core.TestPackage/TestMessageListener.cs
+++ b/src/wix/WixInternal.Core.TestPackage/TestMessageListener.cs
@@ -1,10 +1,12 @@
-using System.Collections.Generic;
-using WixToolset.Data;
-using WixToolset.Extensibility;
-using WixToolset.Extensibility.Services;
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
+    using System.Collections.Generic;
+    using WixToolset.Data;
+    using WixToolset.Extensibility;
+    using WixToolset.Extensibility.Services;
+
     /// <summary>
     /// An <see cref="IMessageListener"/> that simply stores all the messages.
     /// </summary>
diff --git a/src/wix/WixToolset.Core.TestPackage/WixToolset.Core.TestPackage.csproj b/src/wix/WixInternal.Core.TestPackage/WixInternal.Core.TestPackage.csproj
index 3a028ec1..3c56ee86 100644
--- a/src/wix/WixToolset.Core.TestPackage/WixToolset.Core.TestPackage.csproj
+++ b/src/wix/WixInternal.Core.TestPackage/WixInternal.Core.TestPackage.csproj
@@ -27,7 +27,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/wix/WixToolset.Core.TestPackage/WixToolset.Core.TestPackage.v3.ncrunchproject b/src/wix/WixInternal.Core.TestPackage/WixInternal.Core.TestPackage.v3.ncrunchproject
index cff5044e..cff5044e 100644
--- a/src/wix/WixToolset.Core.TestPackage/WixToolset.Core.TestPackage.v3.ncrunchproject
+++ b/src/wix/WixInternal.Core.TestPackage/WixInternal.Core.TestPackage.v3.ncrunchproject
diff --git a/src/wix/WixToolset.Core.TestPackage/WixRunner.cs b/src/wix/WixInternal.Core.TestPackage/WixRunner.cs
index 8ad3af9a..e2420a6b 100644
--- a/src/wix/WixToolset.Core.TestPackage/WixRunner.cs
+++ b/src/wix/WixInternal.Core.TestPackage/WixRunner.cs
@@ -1,11 +1,11 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
-    using System;
     using System.Collections.Generic;
     using System.Threading;
     using System.Threading.Tasks;
+    using WixToolset.Core;
     using WixToolset.Core.Burn;
     using WixToolset.Core.ExtensionCache;
     using WixToolset.Core.WindowsInstaller;
diff --git a/src/wix/WixToolset.Core.TestPackage/WixRunnerResult.cs b/src/wix/WixInternal.Core.TestPackage/WixRunnerResult.cs
index 6a3d714c..9e7fa2f0 100644
--- a/src/wix/WixToolset.Core.TestPackage/WixRunnerResult.cs
+++ b/src/wix/WixInternal.Core.TestPackage/WixRunnerResult.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
     using System;
     using System.Collections.Generic;
diff --git a/src/wix/WixToolset.Core.TestPackage/XmlNodeExtensions.cs b/src/wix/WixInternal.Core.TestPackage/XmlNodeExtensions.cs
index 2f4c1aa3..4fb9b705 100644
--- a/src/wix/WixToolset.Core.TestPackage/XmlNodeExtensions.cs
+++ b/src/wix/WixInternal.Core.TestPackage/XmlNodeExtensions.cs
@@ -1,6 +1,6 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
-namespace WixToolset.Core.TestPackage
+namespace WixInternal.Core.TestPackage
 {
     using System.Collections.Generic;
     using System.IO;
diff --git a/src/wix/WixToolset.BuildTasks/WixToolset.BuildTasks.csproj b/src/wix/WixToolset.BuildTasks/WixToolset.BuildTasks.csproj
index 8088462f..2938abe2 100644
--- a/src/wix/WixToolset.BuildTasks/WixToolset.BuildTasks.csproj
+++ b/src/wix/WixToolset.BuildTasks/WixToolset.BuildTasks.csproj
@@ -13,7 +13,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Build.Tasks.Core" />
-    <PackageReference Include="WixToolset.BaseBuildTasks.Sources" />
+    <PackageReference Include="WixInternal.BaseBuildTasks.Sources" />
     <PackageReference Include="WixToolset.Dtf.WindowsInstaller" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/pack_t.proj b/src/wix/pack_t.proj
index a775ddb3..cd2cf634 100644
--- a/src/wix/pack_t.proj
+++ b/src/wix/pack_t.proj
@@ -7,7 +7,7 @@
     <ProjectReference Include="WixToolset.Core\WixToolset.Core.csproj" Properties="NoBuild=true" Targets="Pack" />
     <ProjectReference Include="WixToolset.Core.Burn\WixToolset.Core.Burn.csproj" Properties="NoBuild=true" Targets="Pack" />
     <ProjectReference Include="WixToolset.Core.ExtensionCache\WixToolset.Core.ExtensionCache.csproj" Properties="NoBuild=true" Targets="Pack" />
-    <ProjectReference Include="WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj" Properties="NoBuild=true" Targets="Pack" />
+    <ProjectReference Include="WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj" Properties="NoBuild=true" Targets="Pack" />
     <ProjectReference Include="WixToolset.Core.WindowsInstaller\WixToolset.Core.WindowsInstaller.csproj" Properties="NoBuild=true" Targets="Pack" />
 
     <ProjectReference Include="WixToolset.Converters\WixToolset.Converters.csproj" Properties="NoBuild=true" Targets="Pack" />
diff --git a/src/wix/test/CompileCoreTestExtensionWixlib/CompileCoreTestExtensionWixlib.csproj b/src/wix/test/CompileCoreTestExtensionWixlib/CompileCoreTestExtensionWixlib.csproj
index 03a805f2..b526a209 100644
--- a/src/wix/test/CompileCoreTestExtensionWixlib/CompileCoreTestExtensionWixlib.csproj
+++ b/src/wix/test/CompileCoreTestExtensionWixlib/CompileCoreTestExtensionWixlib.csproj
@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\..\WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj" />
+    <ProjectReference Include="..\..\WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/wix/test/CompileCoreTestExtensionWixlib/Program.cs b/src/wix/test/CompileCoreTestExtensionWixlib/Program.cs
index 323b5e5e..a6c88ddb 100644
--- a/src/wix/test/CompileCoreTestExtensionWixlib/Program.cs
+++ b/src/wix/test/CompileCoreTestExtensionWixlib/Program.cs
@@ -1,7 +1,7 @@
 // Copyright(c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
 
 using System.Collections.Generic;
-using WixToolset.Core.TestPackage;
+using WixInternal.Core.TestPackage;
 
 namespace CompileCoreTestExtensionWixlib
 {
diff --git a/src/wix/test/WixToolsetTest.BuildTasks/WixBuildTaskFixture.cs b/src/wix/test/WixToolsetTest.BuildTasks/WixBuildTaskFixture.cs
index 92ee441a..3d110b81 100644
--- a/src/wix/test/WixToolsetTest.BuildTasks/WixBuildTaskFixture.cs
+++ b/src/wix/test/WixToolsetTest.BuildTasks/WixBuildTaskFixture.cs
@@ -7,7 +7,7 @@ namespace WixToolsetTest.BuildTasks
     using System.Linq;
     using System.Runtime.InteropServices;
     using Microsoft.Build.Utilities;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.BuildTasks;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
diff --git a/src/wix/test/WixToolsetTest.BuildTasks/WixToolsetTest.BuildTasks.csproj b/src/wix/test/WixToolsetTest.BuildTasks/WixToolsetTest.BuildTasks.csproj
index d53dbe02..2d5e8922 100644
--- a/src/wix/test/WixToolsetTest.BuildTasks/WixToolsetTest.BuildTasks.csproj
+++ b/src/wix/test/WixToolsetTest.BuildTasks/WixToolsetTest.BuildTasks.csproj
@@ -22,6 +22,6 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Build.Tasks.Core" />
     <PackageReference Include="WixToolset.Data" />
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/test/WixToolsetTest.Converters.Symbolizer/ConvertSymbolsFixture.cs b/src/wix/test/WixToolsetTest.Converters.Symbolizer/ConvertSymbolsFixture.cs
index 9fb47a9a..ef00738d 100644
--- a/src/wix/test/WixToolsetTest.Converters.Symbolizer/ConvertSymbolsFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters.Symbolizer/ConvertSymbolsFixture.cs
@@ -6,7 +6,7 @@ namespace WixToolsetTest.Converters.Symbolizer
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Wix3 = Microsoft.Tools.WindowsInstallerXml;
     using WixToolset.Converters.Symbolizer;
     using WixToolset.Data;
diff --git a/src/wix/test/WixToolsetTest.Converters.Symbolizer/WixToolsetTest.Converters.Symbolizer.csproj b/src/wix/test/WixToolsetTest.Converters.Symbolizer/WixToolsetTest.Converters.Symbolizer.csproj
index 5e246624..7eea6516 100644
--- a/src/wix/test/WixToolsetTest.Converters.Symbolizer/WixToolsetTest.Converters.Symbolizer.csproj
+++ b/src/wix/test/WixToolsetTest.Converters.Symbolizer/WixToolsetTest.Converters.Symbolizer.csproj
@@ -17,7 +17,7 @@
 
   <ItemGroup>
     <PackageReference Include="WixToolset.Data" />
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/wix/test/WixToolsetTest.Converters/BitnessFixture.cs b/src/wix/test/WixToolsetTest.Converters/BitnessFixture.cs
index e45a9388..2893246e 100644
--- a/src/wix/test/WixToolsetTest.Converters/BitnessFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/BitnessFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/BootstrapperApplicationFixture.cs b/src/wix/test/WixToolsetTest.Converters/BootstrapperApplicationFixture.cs
index 158ab3be..3b08ca81 100644
--- a/src/wix/test/WixToolsetTest.Converters/BootstrapperApplicationFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/BootstrapperApplicationFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/BundleCacheFixture.cs b/src/wix/test/WixToolsetTest.Converters/BundleCacheFixture.cs
index d1ba0cbf..29c16958 100644
--- a/src/wix/test/WixToolsetTest.Converters/BundleCacheFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/BundleCacheFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/ConditionFixture.cs b/src/wix/test/WixToolsetTest.Converters/ConditionFixture.cs
index c9fecc94..d8a55402 100644
--- a/src/wix/test/WixToolsetTest.Converters/ConditionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/ConditionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/ConverterFixture.cs b/src/wix/test/WixToolsetTest.Converters/ConverterFixture.cs
index cd6849d3..bdc67431 100644
--- a/src/wix/test/WixToolsetTest.Converters/ConverterFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/ConverterFixture.cs
@@ -6,7 +6,7 @@ namespace WixToolsetTest.Converters
     using System.IO;
     using System.Linq;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/ConverterIntegrationFixture.cs b/src/wix/test/WixToolsetTest.Converters/ConverterIntegrationFixture.cs
index fdebc6b0..be2bd41c 100644
--- a/src/wix/test/WixToolsetTest.Converters/ConverterIntegrationFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/ConverterIntegrationFixture.cs
@@ -5,10 +5,10 @@ namespace WixToolsetTest.Converters
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolset.Core;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.Converters/CustomActionFixture.cs b/src/wix/test/WixToolsetTest.Converters/CustomActionFixture.cs
index 7389bc35..7d646bd4 100644
--- a/src/wix/test/WixToolsetTest.Converters/CustomActionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/CustomActionFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Converters
     using System;
     using System.IO;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/CustomTableFixture.cs b/src/wix/test/WixToolsetTest.Converters/CustomTableFixture.cs
index 6dd3da97..84467307 100644
--- a/src/wix/test/WixToolsetTest.Converters/CustomTableFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/CustomTableFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/DependencyFixture.cs b/src/wix/test/WixToolsetTest.Converters/DependencyFixture.cs
index 41ded927..202430ae 100644
--- a/src/wix/test/WixToolsetTest.Converters/DependencyFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/DependencyFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/DirectXExtensionFixture.cs b/src/wix/test/WixToolsetTest.Converters/DirectXExtensionFixture.cs
index f72a4a23..ab5e20b6 100644
--- a/src/wix/test/WixToolsetTest.Converters/DirectXExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/DirectXExtensionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/DirectoryFixture.cs b/src/wix/test/WixToolsetTest.Converters/DirectoryFixture.cs
index 3c906320..063554db 100644
--- a/src/wix/test/WixToolsetTest.Converters/DirectoryFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/DirectoryFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/ExePackageFixture.cs b/src/wix/test/WixToolsetTest.Converters/ExePackageFixture.cs
index 68d234ad..79d32958 100644
--- a/src/wix/test/WixToolsetTest.Converters/ExePackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/ExePackageFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Converters
     using System;
     using System.Linq;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/FeatureFixture.cs b/src/wix/test/WixToolsetTest.Converters/FeatureFixture.cs
index 1df94a81..52bedb93 100644
--- a/src/wix/test/WixToolsetTest.Converters/FeatureFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/FeatureFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/FirewallExtensionFixture.cs b/src/wix/test/WixToolsetTest.Converters/FirewallExtensionFixture.cs
index a101019b..3d3fde16 100644
--- a/src/wix/test/WixToolsetTest.Converters/FirewallExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/FirewallExtensionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/IncludeFixture.cs b/src/wix/test/WixToolsetTest.Converters/IncludeFixture.cs
index 2fd8244f..11e4249d 100644
--- a/src/wix/test/WixToolsetTest.Converters/IncludeFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/IncludeFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/LocalizationFixture.cs b/src/wix/test/WixToolsetTest.Converters/LocalizationFixture.cs
index 28f71480..629f2810 100644
--- a/src/wix/test/WixToolsetTest.Converters/LocalizationFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/LocalizationFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/MsuPackageFixture.cs b/src/wix/test/WixToolsetTest.Converters/MsuPackageFixture.cs
index 5ec109b2..a225dca8 100644
--- a/src/wix/test/WixToolsetTest.Converters/MsuPackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/MsuPackageFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Converters
     using System;
     using System.Linq;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/ProductPackageFixture.cs b/src/wix/test/WixToolsetTest.Converters/ProductPackageFixture.cs
index 5ad7ef6f..7a4f5723 100644
--- a/src/wix/test/WixToolsetTest.Converters/ProductPackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/ProductPackageFixture.cs
@@ -5,9 +5,9 @@ namespace WixToolsetTest.Converters
     using System;
     using System.IO;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.Converters/PropertyFixture.cs b/src/wix/test/WixToolsetTest.Converters/PropertyFixture.cs
index e9ace163..90c71950 100644
--- a/src/wix/test/WixToolsetTest.Converters/PropertyFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/PropertyFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/RegistryFixture.cs b/src/wix/test/WixToolsetTest.Converters/RegistryFixture.cs
index 405f5416..b6a69231 100644
--- a/src/wix/test/WixToolsetTest.Converters/RegistryFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/RegistryFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/RemotePayloadFixture.cs b/src/wix/test/WixToolsetTest.Converters/RemotePayloadFixture.cs
index b2640e13..3e39e5f3 100644
--- a/src/wix/test/WixToolsetTest.Converters/RemotePayloadFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/RemotePayloadFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/SequenceFixture.cs b/src/wix/test/WixToolsetTest.Converters/SequenceFixture.cs
index ec6c709b..9013877a 100644
--- a/src/wix/test/WixToolsetTest.Converters/SequenceFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/SequenceFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/TagFixture.cs b/src/wix/test/WixToolsetTest.Converters/TagFixture.cs
index 5e07c83b..1fec46ac 100644
--- a/src/wix/test/WixToolsetTest.Converters/TagFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/TagFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/UIExtensionFixture.cs b/src/wix/test/WixToolsetTest.Converters/UIExtensionFixture.cs
index 786b18d8..41a34f71 100644
--- a/src/wix/test/WixToolsetTest.Converters/UIExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/UIExtensionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/UtilExtensionFixture.cs b/src/wix/test/WixToolsetTest.Converters/UtilExtensionFixture.cs
index 0f23d87b..5ed64277 100644
--- a/src/wix/test/WixToolsetTest.Converters/UtilExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/UtilExtensionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/VSExtensionFixture.cs b/src/wix/test/WixToolsetTest.Converters/VSExtensionFixture.cs
index 7eb81b05..e9d9a211 100644
--- a/src/wix/test/WixToolsetTest.Converters/VSExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/VSExtensionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/VariableFixture.cs b/src/wix/test/WixToolsetTest.Converters/VariableFixture.cs
index b7b7388f..c4304544 100644
--- a/src/wix/test/WixToolsetTest.Converters/VariableFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/VariableFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs b/src/wix/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs
index 16a68895..3a8be025 100644
--- a/src/wix/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs
+++ b/src/wix/test/WixToolsetTest.Converters/Wix4ConversionFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Converters
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Converters;
     using WixToolsetTest.Converters.Mocks;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Converters/WixToolsetTest.Converters.csproj b/src/wix/test/WixToolsetTest.Converters/WixToolsetTest.Converters.csproj
index 9577b512..27bc24b6 100644
--- a/src/wix/test/WixToolsetTest.Converters/WixToolsetTest.Converters.csproj
+++ b/src/wix/test/WixToolsetTest.Converters/WixToolsetTest.Converters.csproj
@@ -19,10 +19,10 @@
     <ProjectReference Include="..\..\WixToolset.Core\WixToolset.Core.csproj" />
     <ProjectReference Include="..\..\WixToolset.Core.Burn\WixToolset.Core.Burn.csproj" />
     <ProjectReference Include="..\..\WixToolset.Core.WindowsInstaller\WixToolset.Core.WindowsInstaller.csproj" />
-    <ProjectReference Include="..\..\WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj" />
+    <ProjectReference Include="..\..\WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj" />
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/test/WixToolsetTest.Core.Native/CabinetFixture.cs b/src/wix/test/WixToolsetTest.Core.Native/CabinetFixture.cs
index e1189549..56bc8fb4 100644
--- a/src/wix/test/WixToolsetTest.Core.Native/CabinetFixture.cs
+++ b/src/wix/test/WixToolsetTest.Core.Native/CabinetFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.CoreNative
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core.Native;
     using WixToolset.Data;
     using Xunit;
@@ -119,7 +119,7 @@ namespace WixToolsetTest.CoreNative
                         var cabFileInfo = enumerated[i];
                         var fileInfo = new FileInfo(files[i]);
 
-                        WixBuildTools.TestSupport.WixAssert.StringEqual(cabFileInfo.FileId, fileInfo.Name);
+                        WixInternal.TestSupport.WixAssert.StringEqual(cabFileInfo.FileId, fileInfo.Name);
                         Assert.Equal(cabFileInfo.Size, fileInfo.Length);
                         Assert.True(cabFileInfo.SameAsDateTime(fileInfo.CreationTime));
                     }
diff --git a/src/wix/test/WixToolsetTest.Core.Native/CertificateHashesFixture.cs b/src/wix/test/WixToolsetTest.Core.Native/CertificateHashesFixture.cs
index 9f8a31f6..a1e28739 100644
--- a/src/wix/test/WixToolsetTest.Core.Native/CertificateHashesFixture.cs
+++ b/src/wix/test/WixToolsetTest.Core.Native/CertificateHashesFixture.cs
@@ -3,7 +3,7 @@
 namespace WixToolsetTest.CoreNative
 {
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core.Native;
     using Xunit;
 
@@ -17,9 +17,9 @@ namespace WixToolsetTest.CoreNative
             var hashes = CertificateHashes.Read(new[] { cabFile });
 
             var hash = hashes.Single();
-            WixBuildTools.TestSupport.WixAssert.StringEqual(cabFile, hash.Path);
-            WixBuildTools.TestSupport.WixAssert.StringEqual("7EC90B3FC3D580EB571210011F1095E149DCC6BB", hash.PublicKey);
-            WixBuildTools.TestSupport.WixAssert.StringEqual("0B13494DB50BC185A34389BBBAA01EDD1CF56350", hash.Thumbprint);
+            WixInternal.TestSupport.WixAssert.StringEqual(cabFile, hash.Path);
+            WixInternal.TestSupport.WixAssert.StringEqual("7EC90B3FC3D580EB571210011F1095E149DCC6BB", hash.PublicKey);
+            WixInternal.TestSupport.WixAssert.StringEqual("0B13494DB50BC185A34389BBBAA01EDD1CF56350", hash.Thumbprint);
             Assert.Null(hash.Exception);
         }
 
@@ -31,7 +31,7 @@ namespace WixToolsetTest.CoreNative
             var hashes = CertificateHashes.Read(new[] { txtFile });
 
             var hash = hashes.Single();
-            WixBuildTools.TestSupport.WixAssert.StringEqual(txtFile, hash.Path);
+            WixInternal.TestSupport.WixAssert.StringEqual(txtFile, hash.Path);
             Assert.Null(hash.Exception);
         }
 
@@ -43,9 +43,9 @@ namespace WixToolsetTest.CoreNative
 
             var hashes = CertificateHashes.Read(new[] { cabFile, txtFile });
 
-            WixBuildTools.TestSupport.WixAssert.StringEqual(cabFile, hashes[0].Path);
-            WixBuildTools.TestSupport.WixAssert.StringEqual("7EC90B3FC3D580EB571210011F1095E149DCC6BB", hashes[0].PublicKey);
-            WixBuildTools.TestSupport.WixAssert.StringEqual("0B13494DB50BC185A34389BBBAA01EDD1CF56350", hashes[0].Thumbprint);
+            WixInternal.TestSupport.WixAssert.StringEqual(cabFile, hashes[0].Path);
+            WixInternal.TestSupport.WixAssert.StringEqual("7EC90B3FC3D580EB571210011F1095E149DCC6BB", hashes[0].PublicKey);
+            WixInternal.TestSupport.WixAssert.StringEqual("0B13494DB50BC185A34389BBBAA01EDD1CF56350", hashes[0].Thumbprint);
             Assert.Null(hashes[0].Exception);
 
             Assert.Equal(txtFile, hashes[1].Path);
diff --git a/src/wix/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj b/src/wix/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
index 67047592..335c26ba 100644
--- a/src/wix/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
+++ b/src/wix/test/WixToolsetTest.Core.Native/WixToolsetTest.Core.Native.csproj
@@ -18,6 +18,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/test/WixToolsetTest.Core/ParserHelperFixture.cs b/src/wix/test/WixToolsetTest.Core/ParserHelperFixture.cs
index 64ae19e4..8bd2de5a 100644
--- a/src/wix/test/WixToolsetTest.Core/ParserHelperFixture.cs
+++ b/src/wix/test/WixToolsetTest.Core/ParserHelperFixture.cs
@@ -4,7 +4,7 @@ namespace WixToolsetTest.Core
 {
     using System;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core;
     using WixToolset.Data;
     using WixToolset.Extensibility.Services;
diff --git a/src/wix/test/WixToolsetTest.Core/PreprocessorFixture.cs b/src/wix/test/WixToolsetTest.Core/PreprocessorFixture.cs
index 55f54cc2..4be37ea1 100644
--- a/src/wix/test/WixToolsetTest.Core/PreprocessorFixture.cs
+++ b/src/wix/test/WixToolsetTest.Core/PreprocessorFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Core
     using System;
     using System.IO;
     using System.Xml;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core;
     using WixToolset.Extensibility.Data;
     using WixToolset.Extensibility.Services;
diff --git a/src/wix/test/WixToolsetTest.Core/WixToolsetTest.Core.csproj b/src/wix/test/WixToolsetTest.Core/WixToolsetTest.Core.csproj
index 6e1b6556..3907aae0 100644
--- a/src/wix/test/WixToolsetTest.Core/WixToolsetTest.Core.csproj
+++ b/src/wix/test/WixToolsetTest.Core/WixToolsetTest.Core.csproj
@@ -12,6 +12,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/AdvertisedTypeLibVersionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/AdvertisedTypeLibVersionFixture.cs
index 106e2483..1cc11bc3 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/AdvertisedTypeLibVersionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/AdvertisedTypeLibVersionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ApprovedExeFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ApprovedExeFixture.cs
index 47b47ef5..23917794 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ApprovedExeFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ApprovedExeFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class ApprovedExeFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
index 4a25d5e7..f571d13b 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BadInputFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BindVariablesFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BindVariablesFixture.cs
index e7752a2a..4301bffd 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BindVariablesFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BindVariablesFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class BindVariablesFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BootstrapperApplicationFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BootstrapperApplicationFixture.cs
index 9bdc9496..495dbfca 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BootstrapperApplicationFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BootstrapperApplicationFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BundleExtractionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BundleExtractionFixture.cs
index 7b4999cc..4f44ca16 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BundleExtractionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BundleExtractionFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BundleFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BundleFixture.cs
index cbfe6f85..2cc7a681 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BundleFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BundleFixture.cs
@@ -9,9 +9,9 @@ namespace WixToolsetTest.CoreIntegration
     using System.Text;
     using System.Xml;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core.Burn;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Burn;
     using WixToolset.Data.Symbols;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BundleManifestFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BundleManifestFixture.cs
index 21157aac..3c97ceb1 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BundleManifestFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BundleManifestFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.Collections.Generic;
     using System.IO;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class BundleManifestFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BundlePackageFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BundlePackageFixture.cs
index 7bf9fc70..2538c0dc 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BundlePackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BundlePackageFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/BurnRemotePayloadSubcommandFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/BurnRemotePayloadSubcommandFixture.cs
index 4d4d3f83..32ff5287 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/BurnRemotePayloadSubcommandFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/BurnRemotePayloadSubcommandFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class BurnRemotePayloadSubcommandFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/CabFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/CabFixture.cs
index 690937d2..f7e5abf5 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/CabFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/CabFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class CabFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ClassFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ClassFixture.cs
index 4aeabc82..9f2b742b 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ClassFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ClassFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class ClassFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/CommandLineFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/CommandLineFixture.cs
index 0d0b7208..0e78dbc0 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/CommandLineFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/CommandLineFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class CommandLineFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ComponentFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ComponentFixture.cs
index d24ba08c..94900ee0 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ComponentFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ComponentFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ContainerFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ContainerFixture.cs
index febc50d4..f0495853 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ContainerFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ContainerFixture.cs
@@ -6,9 +6,9 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core.Burn.Bundles;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.WindowsInstaller;
     using WixToolset.Data.WindowsInstaller.Rows;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/CopyFileFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/CopyFileFixture.cs
index a7b4a96a..6b670966 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/CopyFileFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/CopyFileFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/CustomActionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/CustomActionFixture.cs
index 2ad6bac2..fea82267 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/CustomActionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/CustomActionFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class CustomActionFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/CustomTableFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/CustomTableFixture.cs
index 1be7d9ab..1b1955fd 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/CustomTableFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/CustomTableFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class CustomTableFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/DecompileFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/DecompileFixture.cs
index b43d2033..77311302 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/DecompileFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/DecompileFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class DecompileFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/DependencyExtensionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/DependencyExtensionFixture.cs
index 89c54c7e..915e1594 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/DependencyExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/DependencyExtensionFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class DependencyExtensionFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs
index 429b69ef..8e401c40 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.WindowsInstaller;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ExePackageFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ExePackageFixture.cs
index 2a4ac51b..7403f96d 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ExePackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ExePackageFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class ExePackageFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ExtensionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ExtensionFixture.cs
index aabaac42..88b8a953 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ExtensionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ExtensionFixture.cs
@@ -7,8 +7,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.Linq;
     using System.Text.RegularExpressions;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/FeatureFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/FeatureFixture.cs
index 2e371794..c6da19eb 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/FeatureFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/FeatureFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/LanguageFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/LanguageFixture.cs
index db9708a7..8dc135eb 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/LanguageFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/LanguageFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/LinkerFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/LinkerFixture.cs
index b6366286..4478e0ea 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/LinkerFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/LinkerFixture.cs
@@ -6,9 +6,9 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Extensibility.Data;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MediaFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MediaFixture.cs
index 6cb94de2..cf94df0b 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MediaFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MediaFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ModuleFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ModuleFixture.cs
index 89ad7bc7..4a3749fd 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ModuleFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ModuleFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsiCabinetFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsiCabinetFixture.cs
index 8bb790d4..bc39e4d3 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsiCabinetFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsiCabinetFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsiFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsiFixture.cs
index fe5f8e63..e83fe4f0 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsiFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsiFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsiPackageFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsiPackageFixture.cs
index 011dbca5..f84882fc 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsiPackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsiPackageFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class MsiPackageFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
index e7a527c4..bc5f7f1d 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class MsiQueryFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsiTransactionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsiTransactionFixture.cs
index f4949171..5cf5dae0 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsiTransactionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsiTransactionFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.Collections.Generic;
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class MsiTransactionFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/MsuPackageFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/MsuPackageFixture.cs
index 28cb0eb5..7284181f 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/MsuPackageFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/MsuPackageFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class MsuPackageFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/PackagePayloadFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/PackagePayloadFixture.cs
index f817317d..1d291a7c 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/PackagePayloadFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/PackagePayloadFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class PackagePayloadFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/PatchFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/PatchFixture.cs
index ca197d9f..69aa9c95 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/PatchFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/PatchFixture.cs
@@ -14,8 +14,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.Xml;
     using System.Xml.Linq;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Burn;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/PayloadFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/PayloadFixture.cs
index cd27ff14..5976a2d2 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/PayloadFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/PayloadFixture.cs
@@ -7,8 +7,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/PreprocessorFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/PreprocessorFixture.cs
index 3c023c2b..f735b53a 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/PreprocessorFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/PreprocessorFixture.cs
@@ -4,9 +4,9 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Extensibility.Data;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/RegistryFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/RegistryFixture.cs
index f0a2e7c9..7bf10e3f 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/RegistryFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/RegistryFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/RollbackBoundaryFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/RollbackBoundaryFixture.cs
index 6d089e79..f8d46c24 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/RollbackBoundaryFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/RollbackBoundaryFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class RollbackBoundaryFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ShortcutFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ShortcutFixture.cs
index 3b6c50c0..968046df 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ShortcutFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ShortcutFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class ShortcutFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/SigningFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/SigningFixture.cs
index 02fbfc30..6e60f4f8 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/SigningFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/SigningFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class SigningFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/SoftwareTagFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/SoftwareTagFixture.cs
index 544fcbda..a98e4683 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/SoftwareTagFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/SoftwareTagFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/TestXmlFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/TestXmlFixture.cs
index ef1f6aee..63add96c 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/TestXmlFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/TestXmlFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.Collections.Generic;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using Xunit;
 
     public class TestXmlFixture
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/TransformFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/TransformFixture.cs
index d69e0222..c4fa6200 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/TransformFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/TransformFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data.WindowsInstaller;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/UIFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/UIFixture.cs
index 728e6c9e..8cd06331 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/UIFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/UIFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/UnadvertisedTypeLibVersionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/UnadvertisedTypeLibVersionFixture.cs
index 247902c1..056b158a 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/UnadvertisedTypeLibVersionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/UnadvertisedTypeLibVersionFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/UpgradeFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/UpgradeFixture.cs
index a9c9fb13..2b6590ee 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/UpgradeFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/UpgradeFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/ValidationFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/ValidationFixture.cs
index 716d3d3a..156990cc 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/ValidationFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/ValidationFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using WixToolset.Data.WindowsInstaller;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/VariableResolverFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/VariableResolverFixture.cs
index f8331a86..a40eb366 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/VariableResolverFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/VariableResolverFixture.cs
@@ -4,7 +4,7 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.Collections.Generic;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using WixToolset.Core;
     using WixToolset.Data;
     using WixToolset.Data.Bind;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/VersionFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/VersionFixture.cs
index f17a92e0..facc772d 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/VersionFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/VersionFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using System.Xml;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/WarningFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/WarningFixture.cs
index 0d5b3b4b..32785bde 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/WarningFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/WarningFixture.cs
@@ -3,8 +3,8 @@
 namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using Xunit;
 
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj b/src/wix/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
index 8b35a85a..7d7c9a0c 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
@@ -16,11 +16,11 @@
     <ProjectReference Include="..\..\WixToolset.Core\WixToolset.Core.csproj" />
     <ProjectReference Include="..\..\WixToolset.Core.Burn\WixToolset.Core.Burn.csproj" />
     <ProjectReference Include="..\..\WixToolset.Core.WindowsInstaller\WixToolset.Core.WindowsInstaller.csproj" />
-    <ProjectReference Include="..\..\WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj" />
+    <ProjectReference Include="..\..\WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj" />
     <ProjectReference Include="..\Example.Extension\Example.Extension.csproj" />
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" />
+    <PackageReference Include="WixInternal.TestSupport" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/WixiplFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/WixiplFixture.cs
index 27ab06fd..ab2729bb 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/WixiplFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/WixiplFixture.cs
@@ -5,8 +5,8 @@ namespace WixToolsetTest.CoreIntegration
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Example.Extension;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/WixlibFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/WixlibFixture.cs
index 428cfc3e..76326741 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/WixlibFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/WixlibFixture.cs
@@ -6,8 +6,8 @@ namespace WixToolsetTest.CoreIntegration
     using System.IO;
     using System.Linq;
     using Example.Extension;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.CoreIntegration/WixlibQueryFixture.cs b/src/wix/test/WixToolsetTest.CoreIntegration/WixlibQueryFixture.cs
index 57351b27..4bed0142 100644
--- a/src/wix/test/WixToolsetTest.CoreIntegration/WixlibQueryFixture.cs
+++ b/src/wix/test/WixToolsetTest.CoreIntegration/WixlibQueryFixture.cs
@@ -4,8 +4,8 @@ namespace WixToolsetTest.CoreIntegration
 {
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
-    using WixToolset.Core.TestPackage;
+    using WixInternal.TestSupport;
+    using WixInternal.Core.TestPackage;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
     using Xunit;
diff --git a/src/wix/test/WixToolsetTest.Sdk/MsbuildFixture.cs b/src/wix/test/WixToolsetTest.Sdk/MsbuildFixture.cs
index c1fdd548..64d05a59 100644
--- a/src/wix/test/WixToolsetTest.Sdk/MsbuildFixture.cs
+++ b/src/wix/test/WixToolsetTest.Sdk/MsbuildFixture.cs
@@ -6,7 +6,7 @@ namespace WixToolsetTest.Sdk
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     public class MsbuildFixture
diff --git a/src/wix/test/WixToolsetTest.Sdk/MsbuildValidationFixture.cs b/src/wix/test/WixToolsetTest.Sdk/MsbuildValidationFixture.cs
index 829ee9c1..82e72e6b 100644
--- a/src/wix/test/WixToolsetTest.Sdk/MsbuildValidationFixture.cs
+++ b/src/wix/test/WixToolsetTest.Sdk/MsbuildValidationFixture.cs
@@ -5,7 +5,7 @@ namespace WixToolsetTest.Sdk
     using System;
     using System.IO;
     using System.Linq;
-    using WixBuildTools.TestSupport;
+    using WixInternal.TestSupport;
     using Xunit;
 
     // When these tests are run repeatedly, they will expose an issue
diff --git a/src/wix/test/WixToolsetTest.Sdk/WixToolsetTest.Sdk.csproj b/src/wix/test/WixToolsetTest.Sdk/WixToolsetTest.Sdk.csproj
index 3ec0eeaf..7fe39da3 100644
--- a/src/wix/test/WixToolsetTest.Sdk/WixToolsetTest.Sdk.csproj
+++ b/src/wix/test/WixToolsetTest.Sdk/WixToolsetTest.Sdk.csproj
@@ -14,10 +14,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\..\WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj" />
+    <ProjectReference Include="..\..\WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj" />
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="WixBuildTools.TestSupport" /> 
+    <PackageReference Include="WixInternal.TestSupport" /> 
   </ItemGroup>
 </Project>
diff --git a/src/wix/wix.cmd b/src/wix/wix.cmd
index c0a1c384..7982fbea 100644
--- a/src/wix/wix.cmd
+++ b/src/wix/wix.cmd
@@ -69,7 +69,7 @@ msbuild pack_t.proj -p:Configuration=%_C% -nologo -m -warnaserror -bl:%_L%\wix_p
 @rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.core.burn" 2> nul
 @rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.core.native" 2> nul
 @rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.core.windowsinstaller" 2> nul
-@rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.core.testpackage" 2> nul
+@rd /s/q "%USERPROFILE%\.nuget\packages\wixinternal.core.testpackage" 2> nul
 @rd /s/q "%USERPROFILE%\.nuget\packages\wixtoolset.sdk" 2> nul
 @exit /b
 
diff --git a/src/wix/wix.sln b/src/wix/wix.sln
index cffaf9ed..f64b22c0 100644
--- a/src/wix/wix.sln
+++ b/src/wix/wix.sln
@@ -24,7 +24,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Example.Extension", "test\E
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixToolsetTest.CoreIntegration", "test\WixToolsetTest.CoreIntegration\WixToolsetTest.CoreIntegration.csproj", "{E8A08E86-1780-4ED4-8F63-AB2B52C1C16B}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixToolset.Core.TestPackage", "WixToolset.Core.TestPackage\WixToolset.Core.TestPackage.csproj", "{853716DB-C02C-41BD-91BC-79CDC0C17D10}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixInternal.Core.TestPackage", "WixInternal.Core.TestPackage\WixInternal.Core.TestPackage.csproj", "{853716DB-C02C-41BD-91BC-79CDC0C17D10}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "CompileCoreTestExtensionWixlib", "test\CompileCoreTestExtensionWixlib\CompileCoreTestExtensionWixlib.csproj", "{23FC60D7-B101-42F8-9786-DB7A9CD964A2}"
 EndProject