diff --git a/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X.Compiler.csproj b/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X.Compiler.csproj
index bbdec08a718..d2882f3e6f3 100644
--- a/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X.Compiler.csproj
+++ b/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version1_X.Compiler.csproj
@@ -5,7 +5,7 @@
     <PreserveCompilationContext>true</PreserveCompilationContext>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <PackageReference Include="System.Diagnostics.DiagnosticSource" />
     <PackageReference Include="System.Text.Encodings.Web" />
   </ItemGroup>
diff --git a/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X.Compiler.csproj b/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X.Compiler.csproj
index bbdec08a718..d2882f3e6f3 100644
--- a/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X.Compiler.csproj
+++ b/src/Compiler/test/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X/Microsoft.AspNetCore.Razor.Test.MvcShim.Version2_X.Compiler.csproj
@@ -5,7 +5,7 @@
     <PreserveCompilationContext>true</PreserveCompilationContext>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <PackageReference Include="System.Diagnostics.DiagnosticSource" />
     <PackageReference Include="System.Text.Encodings.Web" />
   </ItemGroup>
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Microsoft.AspNetCore.Razor.ProjectEngineHost.csproj b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Microsoft.AspNetCore.Razor.ProjectEngineHost.csproj
index 3e1f302dc61..ff110ab5bd9 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Microsoft.AspNetCore.Razor.ProjectEngineHost.csproj
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Microsoft.AspNetCore.Razor.ProjectEngineHost.csproj
@@ -16,7 +16,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
     <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.Common" />
     <PackageReference Include="MessagePack" />
-    <PackageReference Include="System.Threading.Tasks.Extensions" />
+    <PackageReference Include="System.Threading.Tasks.Extensions" Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
     <PackageReference Include="Microsoft.VisualStudio.Threading" />
   </ItemGroup>
 
diff --git a/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Microsoft.AspNetCore.Razor.Test.Common.csproj b/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Microsoft.AspNetCore.Razor.Test.Common.csproj
index 389e6c60fee..83a6f29dc8a 100644
--- a/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Microsoft.AspNetCore.Razor.Test.Common.csproj
+++ b/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Microsoft.AspNetCore.Razor.Test.Common.csproj
@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\Compiler\Microsoft.CodeAnalysis.Razor.Compiler\src\Microsoft.CodeAnalysis.Razor.Compiler.csproj" />
-    <PackageReference Include="Microsoft.CSharp" />
+    <PackageReference Include="Microsoft.CSharp" Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
     <PackageReference Include="Microsoft.CodeAnalysis.Common" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
     <PackageReference Include="Microsoft.CodeAnalysis.Test.Utilities" />