diff --git a/lib/Bitcode/Writer/ValueEnumerator.h b/lib/Bitcode/Writer/ValueEnumerator.h
index d78fdb8af95..3d3cbff8d0e 100644
--- a/lib/Bitcode/Writer/ValueEnumerator.h
+++ b/lib/Bitcode/Writer/ValueEnumerator.h
@@ -94,7 +94,7 @@ public:
   const std::vector<const BasicBlock*> &getBasicBlocks() const {
     return BasicBlocks; 
   }
-  const std::vector<const ParamAttrsList*> getParamAttrs() const {
+  const std::vector<const ParamAttrsList*> &getParamAttrs() const {
     return ParamAttrs;
   }