diff --git a/test/CodeGen/builtins.c b/test/CodeGen/builtins.c
index 35a588e..ac59b27 100644
--- a/test/CodeGen/builtins.c
+++ b/test/CodeGen/builtins.c
@@ -117,7 +117,7 @@
 
 
 
-char *strcat(char *, char const *) {}
+char *strcat(char *a, char const *b) {}
 
 void foo() {
  __builtin_strcat(0, 0);