diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -2915,7 +2915,8 @@
   }
   if (ClEventCallbacks) {
     IRB.CreateCall(DFSF.DFS.DFSanMemTransferCallbackFn,
-                   {RawDestShadow, I.getLength()});
+                   {RawDestShadow,
+                    IRB.CreateZExtOrTrunc(I.getLength(), DFSF.DFS.IntptrTy)});
   }
 }