diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 881e05193ac97b..9d67f2e4d4a6e2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1342,7 +1342,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 	if (copy == 0) {
 		u64 snd_una = READ_ONCE(msk->snd_una);
 
-		if (snd_una != msk->snd_nxt) {
+		if (snd_una != msk->snd_nxt || tcp_write_queue_tail(ssk)) {
 			tcp_remove_empty_skb(ssk);
 			return 0;
 		}
@@ -1350,11 +1350,6 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 		zero_window_probe = true;
 		data_seq = snd_una - 1;
 		copy = 1;
-
-		/* all mptcp-level data is acked, no skbs should be present into the
-		 * ssk write queue
-		 */
-		WARN_ON_ONCE(reuse_skb);
 	}
 
 	copy = min_t(size_t, copy, info->limit - info->sent);
@@ -1383,7 +1378,6 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 	if (reuse_skb) {
 		TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
 		mpext->data_len += copy;
-		WARN_ON_ONCE(zero_window_probe);
 		goto out;
 	}