diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 4ace52e4211a..fbf2b2676073 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3706,6 +3706,7 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
 	WRITE_ONCE(msk->write_seq, subflow->idsn);
 	WRITE_ONCE(msk->snd_nxt, subflow->idsn);
+	WRITE_ONCE(msk->snd_una, subflow->idsn);
 	if (likely(!__mptcp_check_fallback(msk)))
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE);