--- extensions/libipt_ULOG.c	2015-05-13 11:59:59.752055326 -0400
+++ extensions/libipt_ULOG.new.c	2015-05-13 12:09:29.410078607 -0400
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <xtables.h>
+#define ffs(i) __builtin_ffs(i)
 /* For 64bit kernel / 32bit userspace */
 #include <linux/netfilter_ipv4/ipt_ULOG.h>