diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d873621..566ea6c 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -116,7 +116,6 @@
 #include <linux/mroute.h>
 #endif
 
-extern void ip_mc_drop_socket(struct sock *sk);
 
 /* The inetsw table contains everything that inet_create needs to
  * build a new socket.