diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 9082b9d75ac..7ab79ad3cf3 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1682,7 +1682,7 @@ void BoUpSLP::optimizeGatherSequence() {
   for (SmallVectorImpl<BasicBlock *>::iterator I = CSEWorkList.begin(),
                                                E = CSEWorkList.end();
        I != E; ++I) {
-    assert(I == CSEWorkList.begin() || !DT->dominates(*I, *llvm::prior(I)) &&
+    assert((I == CSEWorkList.begin() || !DT->dominates(*I, *llvm::prior(I))) &&
            "Worklist not sorted properly!");
     BasicBlock *BB = *I;
     // For all instructions in blocks containing gather sequences: