diff --git a/include/net/tcp.h b/include/net/tcp.h
index 98ca797..5478356 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -389,6 +389,7 @@
 extern void tcp_clear_retrans(struct tcp_sock *tp);
 extern void tcp_update_metrics(struct sock *sk);
 extern void tcp_init_metrics(struct sock *sk);
+extern bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst);
 extern void tcp_disable_fack(struct tcp_sock *tp);
 extern void tcp_close(struct sock *sk, long timeout);
 extern void tcp_init_sock(struct sock *sk);