1 files changed, 6 insertions, 1 deletions

diff --git a/src/test/WixToolsetTest.MSBuild/MsbuildUtilities.cs b/src/test/WixToolsetTest.MSBuild/MsbuildUtilities.cs
index 633fffe0..6a6f32e0 100644
--- a/src/test/WixToolsetTest.MSBuild/MsbuildUtilities.cs
+++ b/src/test/WixToolsetTest.MSBuild/MsbuildUtilities.cs
@@ -17,7 +17,7 @@ namespace WixToolsetTest.MSBuild
     {
         public static readonly string WixPropsPath = Path.Combine(new Uri(typeof(MsbuildUtilities).Assembly.CodeBase).AbsolutePath, "..", "..", "publish", "WixToolset.MSBuild", "build", "WixToolset.MSBuild.props");
 
-        public static MsbuildRunnerResult BuildProject(BuildSystem buildSystem, string projectPath, string[] arguments = null, string configuration = "Release")
+        public static MsbuildRunnerResult BuildProject(BuildSystem buildSystem, string projectPath, string[] arguments = null, string configuration = "Release", bool? outOfProc = null)
         {
             var allArgs = new List<string>
             {
@@ -28,6 +28,11 @@ namespace WixToolsetTest.MSBuild
                 "-nr:false",
             };
 
+            if (outOfProc.HasValue)
+            {
+                allArgs.Add($"-p:RunWixToolsOutOfProc={outOfProc.Value}");
+            }
+
             if (arguments != null)
             {
                 allArgs.AddRange(arguments);