diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 321dd42c5..8688f78a3 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -619,7 +619,11 @@ cmTargetTraceDependencies
     for(std::vector<std::string>::const_iterator si = sources.begin();
         si != sources.end(); ++si)
       {
-      this->QueueSource(*si);
+      if(this->SourcesQueued.insert(*si).second)
+        {
+        this->SourceQueue.push(*si);
+        this->Makefile->GetOrCreateSource(*si);
+        }
       }
     }