diff --git a/src/libraries/System.IO.Pipelines/pkg/System.IO.Pipelines.pkgproj b/src/libraries/System.IO.Pipelines/pkg/System.IO.Pipelines.pkgproj
index 517bc698cc6da1..9b454d0d07b4b5 100644
--- a/src/libraries/System.IO.Pipelines/pkg/System.IO.Pipelines.pkgproj
+++ b/src/libraries/System.IO.Pipelines/pkg/System.IO.Pipelines.pkgproj
@@ -11,7 +11,12 @@
     </ProjectReference>
     <ProjectReference Include="..\src\System.IO.Pipelines.csproj" />
     <HarvestIncludePaths Include="lib/netstandard1.3" />
-    <InboxOnTargetFramework Include="net5.0" />
+
+    <!-- Even though this library is inbox we want to treat it as out
+         of box in the package so that we can continue to evolve it. -->
+    <ValidatePackageSuppression Include="TreatAsOutOfBox">
+      <Value>.NETCoreApp</Value>
+    </ValidatePackageSuppression>
   </ItemGroup>
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />
 </Project>