diff --git a/lib/VMCore/PassManager.cpp b/lib/VMCore/PassManager.cpp
index 20fc68c4748..29a6df0d6a7 100644
--- a/lib/VMCore/PassManager.cpp
+++ b/lib/VMCore/PassManager.cpp
@@ -1581,7 +1581,7 @@ void ModulePass::assignPassManager(PMStack &PMS,
     else
       break;
   }
-
+  assert(!PMS.empty() && "Unable to find appropriate Pass Manager");
   PMS.top()->add(this);
 }