diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 3c3f630f4943..081c8d00472d 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3398,6 +3398,7 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 
 	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(sock->sk), MPTCP_MIB_MPCAPABLEACTIVE);