diff --git a/dir.props b/dir.props
index 9f6f8e636e..78bfe5c2a1 100644
--- a/dir.props
+++ b/dir.props
@@ -83,11 +83,6 @@
 
   <Import Project="$(TargetInfoProps)" Condition="$(GeneratingStaticPropertiesFile) != 'true' AND Exists('$(TargetInfoProps)')" />
 
-  <PropertyGroup>
-    <!-- Always build portable runtime on OSX to match the CLI repo's filename expectations. https://github.com/dotnet/source-build/issues/438 -->
-    <PortableBuild Condition="'$(TargetOS)' == 'OSX'">true</PortableBuild>
-  </PropertyGroup>
-
   <Import Project="$(ProjectDir)dependencies.props" />
 
   <PropertyGroup>
diff --git a/repos/cli.proj b/repos/cli.proj
index 705c66d5cd..4a754caa3b 100644
--- a/repos/cli.proj
+++ b/repos/cli.proj
@@ -2,7 +2,15 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))/dir.props" />
   <PropertyGroup>
-    <RuntimeArg Condition="'$(TargetOS)' == 'Linux'">--runtime-id $(TargetRid)</RuntimeArg>
+    <!-- CLI will always use the portable core-setup build for OSX anyway.  Turning this on for
+         an OSX build will make it try to use linux-x64 instead of osx-64.  -->
+    <UsePortableLinuxSharedFramework>$(PortableBuild)</UsePortableLinuxSharedFramework>
+    <UsePortableLinuxSharedFramework Condition="'$(TargetOS)' == 'OSX'">false</UsePortableLinuxSharedFramework>
+    <OverrideTargetRid>$(TargetRid)</OverrideTargetRid>
+    <OverrideTargetRid Condition="'$(TargetOS)' == 'OSX'">osx-x64</OverrideTargetRid>
+
+    <RuntimeArg>--runtime-id $(OverrideTargetRid)</RuntimeArg>
+
     <BuildCommandArgs>--stage0 $(DotNetCliToolDir) $(RuntimeArg)</BuildCommandArgs>
 
     <!--
@@ -20,7 +28,7 @@
     <BuildCommandArgs>$(BuildCommandArgs) /p:SkipBuildingInstallers=true</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:IncludeNuGetPackageArchive=false</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:IncludeAdditionalSharedFrameworks=false</BuildCommandArgs>
-    <BuildCommandArgs>$(BuildCommandArgs) /p:UsePortableLinuxSharedFramework=false</BuildCommandArgs>
+    <BuildCommandArgs>$(BuildCommandArgs) /p:UsePortableLinuxSharedFramework=$(UsePortableLinuxSharedFramework)</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:IncludeSharedFrameworksForBackwardsCompatibilityTests=false</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:IncludeMSBuildSdkResolver=false</BuildCommandArgs>
     <BuildCommandArgs>$(BuildCommandArgs) /p:DefaultTargetLatestAspNetCoreRuntimePatch=true</BuildCommandArgs>
@@ -32,9 +40,7 @@
 
     <BuildCommand>$(ProjectDirectory)build$(ShellExtension) $(BuildCommandArgs)</BuildCommand>
 
-    <PackageOutputRid Condition="'$(TargetOS)' == 'Windows_NT'">win-x64</PackageOutputRid>
-    <PackageOutputRid Condition="'$(TargetOS)' == 'OSX'">osx-x64</PackageOutputRid>
-    <PackageOutputRid Condition="'$(PackageOutputRid)' == ''">$(TargetRid)</PackageOutputRid>
+    <PackageOutputRid Condition="'$(PackageOutputRid)' == ''">$(OverrideTargetRid)</PackageOutputRid>
     <PackagesOutput>$(ProjectDirectory)bin/2/$(PackageOutputRid)/packages/</PackagesOutput>
     <TarBallOutput>$(PackagesOutput)</TarBallOutput>
     <RepoApiImplemented>false</RepoApiImplemented>
diff --git a/repos/core-setup.proj b/repos/core-setup.proj
index de698ea626..299f4a2087 100644
--- a/repos/core-setup.proj
+++ b/repos/core-setup.proj
@@ -2,9 +2,15 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))/dir.props" />
   <PropertyGroup>
-    <BuildArguments>-ConfigurationGroup=$(Configuration) -PortableBuild=$(PortableBuild) -SkipTests=true </BuildArguments>
+    <!-- CLI uses the portable RID for OSX all the time, so override -->
+    <OverridePortableBuild>$(PortableBuild)</OverridePortableBuild>
+    <OverrideTargetRid>$(TargetRid)</OverrideTargetRid>
+    <OverridePortableBuild Condition="'$(TargetOS)' == 'OSX'">true</OverridePortableBuild>
+    <OverrideTargetRid Condition="'$(TargetOS)' == 'OSX'">osx-x64</OverrideTargetRid>
+
+    <BuildArguments>-ConfigurationGroup=$(Configuration) -PortableBuild=$(OverridePortableBuild) -SkipTests=true </BuildArguments>
     <BuildArguments Condition="$(Platform.Contains('arm'))">$(BuildArguments) -TargetArchitecture=$(Platform) -DisableCrossgen=true -CrossBuild=true</BuildArguments>
-    <BuildCommand>$(ProjectDirectory)/build$(ShellExtension) $(BuildArguments) -- /p:BuildDebPackage=false /p:BuildAllPackages=true /bl</BuildCommand>
+    <BuildCommand>$(ProjectDirectory)/build$(ShellExtension) $(BuildArguments) -- /p:BuildDebPackage=false /p:BuildAllPackages=true /p:OutputRid=$(OverrideTargetRid) /bl</BuildCommand>
     <BuildCommand Condition="$(Platform.Contains('arm'))">$(ArmEnvironmentVariables) $(BuildCommand)</BuildCommand>
     <OfficialBuildId>20180814-02</OfficialBuildId>
 
diff --git a/repos/coreclr.proj b/repos/coreclr.proj
index 78979ca750..e6fa46fe13 100644
--- a/repos/coreclr.proj
+++ b/repos/coreclr.proj
@@ -2,7 +2,11 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))/dir.props" />
   <PropertyGroup>
-    <BuildArguments>$(Platform) $(Configuration) skiptests -PortableBuild=$(PortableBuild) </BuildArguments>
+    <!-- core-setup uses the portable RID for OSX all the time, so override -->
+    <OverridePortableBuild>$(PortableBuild)</OverridePortableBuild>
+    <OverridePortableBuild Condition="'$(TargetOS)' == 'OSX'">true</OverridePortableBuild>
+
+    <BuildArguments>$(Platform) $(Configuration) skiptests -PortableBuild=$(OverridePortableBuild) </BuildArguments>
     <BuildArguments Condition="'$(SkipDisablePgo)' != 'true'">$(BuildArguments) -nopgooptimize</BuildArguments>
     <BuildArguments Condition="'$(OS)' != 'Windows_NT'">$(BuildArguments) msbuildonunsupportedplatform</BuildArguments>
     <BuildArguments Condition="'$(UseSystemLibraries)' == 'true'">$(BuildArguments) cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND=TRUE</BuildArguments>
diff --git a/repos/corefx.proj b/repos/corefx.proj
index c3cc32470f..b776499d0b 100644
--- a/repos/corefx.proj
+++ b/repos/corefx.proj
@@ -2,7 +2,13 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))/dir.props" />
   <PropertyGroup>
-    <BuildArguments>-$(Configuration) -buildArch=$(Platform) -portable=$(PortableBuild) -BuildTests=false</BuildArguments>
+    <!-- OSX core-setup build always uses the portable RID, so override it -->
+    <OverridePortableBuild>$(PortableBuild)</OverridePortableBuild>
+    <OverridePortableBuild Condition="'$(TargetOS)' == 'OSX'">true</OverridePortableBuild>
+    <OverrideTargetRid>$(TargetRid)</OverrideTargetRid>
+    <OverrideTargetRid Condition="'$(TargetOS)' == 'OSX'">osx-x64</OverrideTargetRid>
+
+    <BuildArguments>-$(Configuration) -buildArch=$(Platform) -portable=$(OverridePortableBuild) -BuildTests=false -PackageRid=$(OverrideTargetRid)</BuildArguments>
     <BuildCommand>$(ProjectDirectory)/build$(ShellExtension) $(BuildArguments) -- /p:ILLinkTrimAssembly=false /bl</BuildCommand>
     <BuildCommand Condition="$(Platform.Contains('arm'))">$(ArmEnvironmentVariables) $(BuildCommand)</BuildCommand>
     <PackagesOutput>$(ProjectDirectory)/bin/packages/$(Configuration)</PackagesOutput>
diff --git a/repos/dir.props b/repos/dir.props
index bea8d507cd..8493a27a34 100644
--- a/repos/dir.props
+++ b/repos/dir.props
@@ -42,7 +42,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <EnvironmentVariables Include="DOTNET_RUNTIME_ID=$(TargetRid)" />
     <EnvironmentVariables Include="DOTNET_TOOL_DIR=$(DotNetCliToolDir)" />
     <EnvironmentVariables Include="BUILD_TOOLS_TOOL_DIR=$(ProjectDir)Tools/" />
     <EnvironmentVariables Include="BUILDTOOLS_SKIP_CROSSGEN=1" />
diff --git a/repos/roslyn.proj b/repos/roslyn.proj
index 8867b0cca0..93424a1900 100644
--- a/repos/roslyn.proj
+++ b/repos/roslyn.proj
@@ -13,7 +13,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <EnvironmentVariables Include="DOTNET_RUNTIME_ID=$(TargetRid)" />
     <EnvironmentVariables Include="COMMIT_SHA=$(GitCommitHash)" />
     <EnvironmentVariables Include="NUGET_PACKAGE_VERSION=$(NuGetPackageVersion)" />
   </ItemGroup>
diff --git a/tools-local/init-build.proj b/tools-local/init-build.proj
index 7f390c42a2..f0125f348c 100644
--- a/tools-local/init-build.proj
+++ b/tools-local/init-build.proj
@@ -75,6 +75,12 @@
       <Output PropertyName="TargetOS" TaskParameter="OSName" />
     </GetHostInformation>
 
+    <PropertyGroup Condition="'$(PortableBuild)' == 'true'">
+      <TargetRid Condition="'$(TargetOS)' == 'OSX'">osx-$(Platform)</TargetRid>
+      <TargetRid Condition="'$(TargetOS)' == 'Linux'">linux-$(Platform)</TargetRid>
+      <TargetRid Condition="'$(TargetOS)' == 'Windows_NT'">win-$(Platform)</TargetRid>
+    </PropertyGroup>
+
     <PropertyGroup>
       <TargetInfoPropsContent>&lt;Project ToolsVersion=&quot;15.0&quot;&gt;
   &lt;PropertyGroup&gt;