diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp
index d88088cfe13..4af18ccb2af 100644
--- a/lib/Analysis/MemorySSA.cpp
+++ b/lib/Analysis/MemorySSA.cpp
@@ -260,10 +260,10 @@ static bool instructionClobbersQuery(MemoryDef *MD,
     }
   }
 
-  /*if (UseCS) {
+  if (UseCS) {
     ModRefInfo I = AA.getModRefInfo(DefInst, UseCS);
     return I != MRI_NoModRef;
-  }*/
+  }
 
   if (auto *DefLoad = dyn_cast<LoadInst>(DefInst)) {
     if (auto *UseLoad = dyn_cast<LoadInst>(UseInst)) {