diff --git a/src/SourceBuild/content/Directory.Build.props b/src/SourceBuild/content/Directory.Build.props
index 2f80065a8..c63965543 100644
--- a/src/SourceBuild/content/Directory.Build.props
+++ b/src/SourceBuild/content/Directory.Build.props
@@ -6,6 +6,18 @@
     <DotNetBuildOrchestrator>true</DotNetBuildOrchestrator>
   </PropertyGroup>
 
+  <PropertyGroup Label="ShortStacks">
+    <_OverrideTargetOS>$(OverrideTargetRid.Substring(0, $(OverrideTargetRid.LastIndexOf('-'))))</_OverrideTargetOS>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'wasi'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'browser'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'ios'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'iossimulator'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'tvos'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'tvossimulator'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'maccatalyst'">true</ShortStack>
+    <ShortStack Condition="'$(_OverrideTargetOS)' == 'android'">true</ShortStack>
+  </PropertyGroup>
+
   <PropertyGroup Label="CalculateTargetOS">
     <BuildOS>linux</BuildOS>
     <BuildOS Condition="$([MSBuild]::IsOSPlatform('OSX'))">osx</BuildOS>
@@ -33,7 +45,7 @@
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(BuildArchitecture)' == 's390x'">s390x</TargetArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(BuildArchitecture)' == 'ppc64le'">ppc64le</TargetArchitecture>
 
-    <TargetArchitecture Condition="'$(OverrideTargetRid)' != ''">$(OverrideTargetRid.Substring($(OverrideTargetRid.LastIndexOf('-'))).TrimStart('-'))</TargetArchitecture>
+    <TargetArchitecture Condition="'$(OverrideTargetRid)' != '' and '$(ShortStack)' != 'true'">$(OverrideTargetRid.Substring($(OverrideTargetRid.LastIndexOf('-'))).TrimStart('-'))</TargetArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == ''">x64</TargetArchitecture>
 
     <Platform Condition="'$(Platform)' == '' and '$(InferPlatformFromTargetArchitecture)' == 'true'">$(TargetArchitecture)</Platform>
diff --git a/src/SourceBuild/content/repo-projects/dotnet.proj b/src/SourceBuild/content/repo-projects/dotnet.proj
index 0de74d679..5de28398c 100644
--- a/src/SourceBuild/content/repo-projects/dotnet.proj
+++ b/src/SourceBuild/content/repo-projects/dotnet.proj
@@ -24,6 +24,10 @@
     <RepositoryReference Include="symreader" />
     <RepositoryReference Include="source-build-externals" Condition="'$(DotNetBuildSourceOnly)' == 'true'" />
     <RepositoryReference Include="runtime" />
+  </ItemGroup>
+
+  <!-- Stop build at this point for runtime-only platforms like iOS -->
+  <ItemGroup Condition="'$(ShortStack)' != 'true'">
     <RepositoryReference Include="roslyn" />
     <RepositoryReference Include="windowsdesktop" Condition="'$(TargetOS)' == 'windows'" />
     <RepositoryReference Include="xdt" />
diff --git a/src/SourceBuild/content/repo-projects/runtime.proj b/src/SourceBuild/content/repo-projects/runtime.proj
index 50754cee4..9409f1729 100644
--- a/src/SourceBuild/content/repo-projects/runtime.proj
+++ b/src/SourceBuild/content/repo-projects/runtime.proj
@@ -20,8 +20,8 @@
     <BuildArgs Condition="'$(OverrideTargetArch)' != ''">$(BuildArgs) $(FlagParameterPrefix)arch $(OverrideTargetArch)</BuildArgs>
     <BuildArgs Condition="'$(OverrideTargetOS)' != ''">$(BuildArgs) $(FlagParameterPrefix)os $(OverrideTargetOS)</BuildArgs>
     <BuildArgs>$(BuildArgs) /p:TargetRid=$(OverrideTargetRid)</BuildArgs>
-    <BuildArgs>$(BuildArgs) /p:RuntimeOS=$(RuntimeOS)</BuildArgs>
-    <BuildArgs>$(BuildArgs) /p:BaseOS=$(BaseOS)</BuildArgs>
+    <BuildArgs Condition="'$(ShortStack)' != 'true'">$(BuildArgs) /p:RuntimeOS=$(RuntimeOS)</BuildArgs>
+    <BuildArgs Condition="'$(ShortStack)' != 'true'">$(BuildArgs) /p:BaseOS=$(BaseOS)</BuildArgs>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' == 'true'">