diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index ecf41d52d2fc48d8e7ef73595e966ddea8196ef1..9486720c325663cc3258de4fcbafed05a30331ea 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -695,7 +695,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk,
 	if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1)
 		return subflow->mp_capable;
 
-	if (mp_opt->use_ack) {
+	if (mp_opt->dss && mp_opt->use_ack) {
 		/* subflows are fully established as soon as we get any
 		 * additional ack.
 		 */