diff --git a/cf/broken2.m4 b/cf/broken2.m4
index 01d7e698c..5558b780d 100644
--- a/cf/broken2.m4
+++ b/cf/broken2.m4
@@ -11,7 +11,7 @@ AC_CACHE_VAL(ac_cv_func_[]$1,
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_[]$1) || defined (__stub___[]$1)
+#if defined (__stub_$1) || defined (__stub___$1)
 choke me
 #else
 $1($3)