diff --git a/src/csharp/Grpc.Core.Testing/Grpc.Core.Testing.csproj b/src/csharp/Grpc.Core.Testing/Grpc.Core.Testing.csproj
index 4ada8dea6a60197c9ec3af930c9e6a84e8730ab3..4e186d14dc9631d51dfd071e36c382a138353a44 100755
--- a/src/csharp/Grpc.Core.Testing/Grpc.Core.Testing.csproj
+++ b/src/csharp/Grpc.Core.Testing/Grpc.Core.Testing.csproj
@@ -32,8 +32,6 @@
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
-    <Reference Include="System.Runtime" />
-    <Reference Include="System.IO" />
     <Reference Include="System" />
     <Reference Include="Microsoft.CSharp" />
   </ItemGroup>