diff --git a/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj b/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
index 5b8b97b8c98ef9..4f2d15aa3b6a58 100644
--- a/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
+++ b/src/libraries/Microsoft.Win32.Primitives/src/Microsoft.Win32.Primitives.csproj
@@ -1,28 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)-Browser</TargetFrameworks>
+    <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
+    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="System\ComponentModel\Win32Exception.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
-    <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"
-             Link="Common\Interop\Windows\Interop.Libraries.cs" />
-    <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.FormatMessage.cs"
-             Link="Common\Interop\Windows\Interop.FormatMessage.cs" />
-    <Compile Include="System\ComponentModel\Win32Exception.Windows.cs" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true'">
-    <Compile Include="System\ComponentModel\Win32Exception.Unix.cs" />
-    <Compile Include="$(CommonPath)Interop\Unix\Interop.Libraries.cs"
-             Link="Common\Interop\Unix\Interop.Libraries.cs" />
-    <Compile Include="$(CommonPath)Interop\Unix\Interop.Errors.cs"
-             Link="Common\Interop\Unix\Interop.Errors.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="System.Runtime" />
-    <Reference Include="System.Runtime.InteropServices" />
+    <ProjectReference Include="$(CoreLibProject)" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index c868bff55657a1..5f3a5490294d51 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -230,6 +230,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\DefaultValueAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\EditorBrowsableAttribute.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\EditorBrowsableState.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\Win32Exception.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Configuration\Assemblies\AssemblyHashAlgorithm.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Configuration\Assemblies\AssemblyVersionCompatibility.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Context.cs" />
@@ -1820,6 +1821,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\DateTime.Windows.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.Win32.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.Windows.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\Win32Exception.Windows.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\DebugProvider.Windows.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Stopwatch.Windows.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Tracing\RuntimeEventSourceHelper.Windows.cs" Condition="'$(FeaturePerfTracing)' == 'true'" />
@@ -2101,6 +2103,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Microsoft\Win32\SafeHandles\SafeFileHandle.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\AppDomain.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Buffer.Unix.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\ComponentModel\Win32Exception.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\DateTime.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\DebugProvider.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Stopwatch.Unix.cs" />
diff --git a/src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.Unix.cs
similarity index 100%
rename from src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.Unix.cs
rename to src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.Unix.cs
diff --git a/src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.Windows.cs b/src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.Windows.cs
similarity index 100%
rename from src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.Windows.cs
rename to src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.Windows.cs
diff --git a/src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.cs b/src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.cs
similarity index 100%
rename from src/libraries/Microsoft.Win32.Primitives/src/System/ComponentModel/Win32Exception.cs
rename to src/libraries/System.Private.CoreLib/src/System/ComponentModel/Win32Exception.cs