diff --git a/lib/Lex/MacroInfo.cpp b/lib/Lex/MacroInfo.cpp
index 5abafe1..b61ff71 100644
--- a/lib/Lex/MacroInfo.cpp
+++ b/lib/Lex/MacroInfo.cpp
@@ -110,8 +110,9 @@
       // With syntactic equivalence the parameter names can be different as long
       // as they are used in the same place.
       int AArgNum = getArgumentNum(A.getIdentifierInfo());
-      int BArgNum = Other.getArgumentNum(B.getIdentifierInfo());
-      if (AArgNum == -1 || AArgNum != BArgNum)
+      if (AArgNum == -1)
+        return false;
+      if (AArgNum != Other.getArgumentNum(B.getIdentifierInfo()))
         return false;
       continue;
     }