diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp
index 6fc827ae2b1..f54f04460a4 100644
--- a/lib/Analysis/MemorySSA.cpp
+++ b/lib/Analysis/MemorySSA.cpp
@@ -1726,8 +1726,11 @@ MemoryUseOrDef *MemorySSA::createDefinedAccess(Instruction *I,
   if (CreationMustSucceed)
     assert(NewAccess != nullptr && "Tried to create a memory access for a "
                                    "non-memory touching instruction");
-  if (NewAccess)
+  if (NewAccess) {
+    assert((!Definition || !isa<MemoryUse>(Definition)) &&
+           "A use cannot be a defining access");
     NewAccess->setDefiningAccess(Definition);
+  }
   return NewAccess;
 }