diff --git a/src/Tools/ExternalAccess/RazorCompiler/Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler.csproj b/src/Tools/ExternalAccess/RazorCompiler/Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler.csproj
index d22dd38f7a180..2d12cd6574627 100644
--- a/src/Tools/ExternalAccess/RazorCompiler/Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler.csproj
+++ b/src/Tools/ExternalAccess/RazorCompiler/Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler.csproj
@@ -5,6 +5,9 @@
     <RootNamespace>Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler</RootNamespace>
     <TargetFramework>netstandard2.0</TargetFramework>
 
+    <!-- Used by Razor source generator which is included in source build. -->
+    <ExcludeFromSourceBuild>false</ExcludeFromSourceBuild>
+
     <!-- NuGet -->
     <IsPackable>true</IsPackable>
     <PackageId>Microsoft.CodeAnalysis.ExternalAccess.RazorCompiler</PackageId>