diff --git a/build/Rx.props b/build/Rx.props
index f1526dbf8c..edff0af160 100644
--- a/build/Rx.props
+++ b/build/Rx.props
@@ -1,7 +1,5 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
     <PackageReference Include="System.Reactive" Version="4.1.6" />
-    <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.3" />
-    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.6.0" />
   </ItemGroup>
 </Project>