diff --git a/lib/Analysis/CFLAliasAnalysis.cpp b/lib/Analysis/CFLAliasAnalysis.cpp
index 88bb84a8002..9783671b09a 100644
--- a/lib/Analysis/CFLAliasAnalysis.cpp
+++ b/lib/Analysis/CFLAliasAnalysis.cpp
@@ -774,7 +774,7 @@ static Optional<StratifiedAttr> valueToAttrIndex(Value *Val) {
 }
 
 static StratifiedAttr argNumberToAttrIndex(unsigned ArgNum) {
-  if (ArgNum > AttrMaxNumArgs)
+  if (ArgNum >= AttrMaxNumArgs)
     return AttrAllIndex;
   return ArgNum + AttrFirstArgIndex;
 }