diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 804684c..c70d05e 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -966,7 +966,7 @@
 
     if (HasSideEffects(E->getArg(0), Info.Ctx)) {
       if (E->getArg(1)->EvaluateAsInt(Info.Ctx).getZExtValue() < 2)
-        return Success(-1, E);
+        return Success(-1ULL, E);
       return Success(0, E);
     }