diff --git a/src/SourceBuild/content/repo-projects/aspnetcore.proj b/src/SourceBuild/content/repo-projects/aspnetcore.proj
index 1849b9582016..a19b4ec2eadd 100644
--- a/src/SourceBuild/content/repo-projects/aspnetcore.proj
+++ b/src/SourceBuild/content/repo-projects/aspnetcore.proj
@@ -6,6 +6,8 @@
     <OverrideTargetRid Condition="'$(TargetOS)' == 'OSX'">osx-$(Platform)</OverrideTargetRid>
     <OverrideTargetRid Condition="'$(TargetOS)' == 'FreeBSD'">freebsd-$(Platform)</OverrideTargetRid>
     <OverrideTargetRid Condition="'$(TargetOS)' == 'Windows_NT'">win-$(Platform)</OverrideTargetRid>
+    <_portableRidOverridden Condition="'$(TargetRid)' != '$(OverrideTargetRid)'">true</_portableRidOverridden>
+    <_portableRidOverridden Condition="'$(TargetRid)' == '$(OverrideTargetRid)'">false</_portableRidOverridden>
 
     <!-- StandardSourceBuildArgs include -publish which is not supported by the aspnetcore build script. -->
     <BuildCommandArgs>$(StandardSourceBuildArgs.Replace('--publish', ''))</BuildCommandArgs>
@@ -14,7 +16,7 @@
     <BuildCommandArgs>$(BuildCommandArgs) --no-build-repo-tasks</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) --no-build-nodejs</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:PublishCompressedFilesPathPrefix=$(SourceBuiltAspNetCoreRuntime)</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) /p:PortableBuild=false /p:TargetRuntimeIdentifier=$(OverrideTargetRid)</BuildCommandArgs>
+    <BuildCommandArgs>$(BuildCommandArgs) /p:PortableBuild=$(_portableRidOverridden) /p:TargetRuntimeIdentifier=$(OverrideTargetRid)</BuildCommandArgs>
     <!-- Update to 1.0.0 version of reference assemblies which are built in SBRP instead of the preview.2 version
          included by Arcade -->
     <BuildCommandArgs>$(BuildCommandArgs) /p:MicrosoftNetFrameworkReferenceAssembliesVersion=1.0.0</BuildCommandArgs>