diff --git a/src/mono/msbuild/apple/data/ProxyProjectForAOTOnHelix.proj b/src/mono/msbuild/apple/data/ProxyProjectForAOTOnHelix.proj
index 1bdf85d6403b1..cecadccb58565 100644
--- a/src/mono/msbuild/apple/data/ProxyProjectForAOTOnHelix.proj
+++ b/src/mono/msbuild/apple/data/ProxyProjectForAOTOnHelix.proj
@@ -1,10 +1,12 @@
 <Project DefaultTargets="BundleTestAppleApp" Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TestRootDir Condition="'$(HELIX_WORKITEM_ROOT)' != ''">$(HELIX_WORKITEM_ROOT)\apple_build\</TestRootDir>
-    <TestRootDir Condition="'$(HELIX_WORKITEM_ROOT)' == ''">$(MSBuildThisFileDirectory)..\apple_build\</TestRootDir>
+    <TestRootDir Condition="'$(HELIX_WORKITEM_ROOT)' != ''">$([MSBuild]::NormalizeDirectory($(HELIX_WORKITEM_ROOT), 'apple_build'))</TestRootDir>
+    <TestRootDir Condition="'$(HELIX_WORKITEM_ROOT)' == ''">$([MSBuild]::NormalizeDirectory($(MSBuildThisFileDirectory), '..', 'apple_build'))</TestRootDir>
+
+    <OriginalPublishDir>$([MSBuild]::NormalizeDirectory($(TestRootDir), '..', 'publish'))</OriginalPublishDir>
+    <ExtraFilesPath>$([MSBuild]::NormalizeDirectory($(TestRootDir), '..', 'extraFiles'))</ExtraFilesPath>
+    <BaseIntermediateOutputPath>$([MSBuild]::NormalizeDirectory($(TestRootDir), '..', 'obj'))</BaseIntermediateOutputPath>
 
-    <OriginalPublishDir>$([System.IO.Path]::GetFullPath('$(TestRootDir)..\publish\'))</OriginalPublishDir>
-    <ExtraFilesPath>$(OriginalPublishDir)..\extraFiles\</ExtraFilesPath>
     <AppleBuildDependsOn>_PrepareForAppleBuildAppOnHelix;$(AppleBuildDependsOn);_AfterAppleBuildOnHelix</AppleBuildDependsOn>
   </PropertyGroup>