diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2f061a911bc2c..25e8dc970b985 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -513,8 +513,8 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 		opt = ireq->ipv6_opt;
 		if (!opt)
 			opt = rcu_dereference(np->opt);
-		err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass,
-			       sk->sk_priority);
+		err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt,
+			       np->tclass, sk->sk_priority);
 		rcu_read_unlock();
 		err = net_xmit_eval(err);
 	}