diff --git a/src/Tools/ExternalAccess/OmniSharp/Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.csproj b/src/Tools/ExternalAccess/OmniSharp/Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.csproj
index 58bbeea0165fd..484a9b830d35a 100644
--- a/src/Tools/ExternalAccess/OmniSharp/Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.csproj
+++ b/src/Tools/ExternalAccess/OmniSharp/Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.csproj
@@ -10,6 +10,10 @@
       https://github.com/OmniSharp/omnisharp-roslyn
     </PackageDescription>
   </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\IsExternalInit.cs" Link="IsExternalInit.cs" />
+  </ItemGroup>
   
   <ItemGroup>
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.ExternalAccess.OmniSharp.CSharp" />