2 files changed, 1 insertions, 3 deletions

diff --git a/src/ext/UI/wixext/UIExtensionData.cs b/src/ext/UI/wixext/UIExtensionData.cs
index 32557029..349a5912 100644
--- a/src/ext/UI/wixext/UIExtensionData.cs
+++ b/src/ext/UI/wixext/UIExtensionData.cs
@@ -7,8 +7,6 @@ namespace WixToolset.UI
 
     public sealed class UIExtensionData : BaseExtensionData
     {
-        public override string DefaultCulture => "en-US";
-
         public override bool TryGetSymbolDefinitionByName(string name, out IntermediateSymbolDefinition symbolDefinition)
         {
             symbolDefinition = null;
diff --git a/src/ext/UI/wixlib/WixUI_en-us.wxl b/src/ext/UI/wixlib/WixUI_en-us.wxl
index c9904b61..a06f8b17 100644
--- a/src/ext/UI/wixlib/WixUI_en-us.wxl
+++ b/src/ext/UI/wixlib/WixUI_en-us.wxl
@@ -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. -->
 
 
-<WixLocalization Culture="en-US" Codepage="1252" xmlns="http://wixtoolset.org/schemas/v4/wxl">
+<WixLocalization Culture="en-US" ExtensionDefaultCulture="yes" Codepage="1252" xmlns="http://wixtoolset.org/schemas/v4/wxl">
     <!-- _locID@Culture="en-US" _locComment="American English" -->
     <!-- _locID@Codepage="1252" _locComment="Windows-1252" -->