diff --git a/src/Packages/Microsoft.Internal.Extensions.DotNetApiDocs.Transport/Microsoft.Internal.Extensions.DotNetApiDocs.Transport.proj b/src/Packages/Microsoft.Internal.Extensions.DotNetApiDocs.Transport/Microsoft.Internal.Extensions.DotNetApiDocs.Transport.proj
index aa1d5b37fbc..f9212aeacf8 100644
--- a/src/Packages/Microsoft.Internal.Extensions.DotNetApiDocs.Transport/Microsoft.Internal.Extensions.DotNetApiDocs.Transport.proj
+++ b/src/Packages/Microsoft.Internal.Extensions.DotNetApiDocs.Transport/Microsoft.Internal.Extensions.DotNetApiDocs.Transport.proj
@@ -31,6 +31,7 @@
     <!-- This is needed in order to avoid a version conflict between some dependencies bringing in the 6.0 version of the assembly
     and some others depending on the 9.0 version. -->
     <PackageReference Include="System.Text.Encodings.Web" />
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" />
   </ItemGroup>
 
   <!-- Include the reference assembly and put the documentation file next to it. -->