diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index c4ab42d263f..15109b5bcea 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -3496,7 +3496,7 @@ void ObjCARCOpt::OptimizeWeakCalls(Function &F) {
           // No return value.
           break;
         default:
-          break;
+          llvm_unreachable("alloca really is used!");
         }
         UserInst->eraseFromParent();
       }