Actually moving this to the proper place.
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj b/vsprojects/vcxproj/grpc/grpc.vcxproj
index 438667a..8905695 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj
@@ -708,6 +708,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\census\operation.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\census\placeholders.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\census\tag_set.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\census\tracing.c">