diff --git a/target/linux/generic/patches-3.13/644-bridge_optimize_netfilter_hooks.patch b/target/linux/generic/patches-3.13/644-bridge_optimize_netfilter_hooks.patch
index 23eb2859f1..3d5ea84ab0 100644
--- a/target/linux/generic/patches-3.13/644-bridge_optimize_netfilter_hooks.patch
+++ b/target/linux/generic/patches-3.13/644-bridge_optimize_netfilter_hooks.patch
@@ -100,7 +100,7 @@
  
  /* br_netfilter.c */
  #ifdef CONFIG_BRIDGE_NETFILTER
-+int brnf_call_ebtables;
++extern int brnf_call_ebtables;
  int br_netfilter_init(void);
  void br_netfilter_fini(void);
  void br_netfilter_rtable_init(struct net_bridge *);