diff --git a/include/net/tcp.h b/include/net/tcp.h
index 572a77b..7fd6b77 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -341,7 +341,7 @@
 extern int			tcp_child_process(struct sock *parent,
 						  struct sock *child,
 						  struct sk_buff *skb);
-extern int			tcp_use_frto(const struct sock *sk);
+extern int			tcp_use_frto(struct sock *sk);
 extern void			tcp_enter_frto(struct sock *sk);
 extern void			tcp_enter_loss(struct sock *sk, int how);
 extern void			tcp_clear_retrans(struct tcp_sock *tp);