diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index 5dc4095fbb9..5f27079a96d 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5122,6 +5122,7 @@ LoopVectorizationCostModel::selectVectorizationFactor(bool OptForSize,
   DEBUG(if (ForceVectorization && Width > 1 && Cost >= ScalarCost) dbgs()
         << "LV: Vectorization seems to be not beneficial, "
         << "but was forced by a user.\n");
+  (void)ScalarCost;
   DEBUG(dbgs() << "LV: Selecting VF: "<< Width << ".\n");
   Factor.Width = Width;
   Factor.Cost = Width * Cost;