diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 61f272a..22548b5 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -83,7 +83,8 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb)
 		      tcp_skb_pcount(skb));
 }
 
-/* SND.NXT, if window was not shrunk.
+/* SND.NXT, if window was not shrunk or the amount of shrunk was less than one
+ * window scaling factor due to loss of precision.
  * If window has been shrunk, what should we make? It is not clear at all.
  * Using SND.UNA we will fail to open window, SND.NXT is out of window. :-(
  * Anything in between SND.UNA...SND.UNA+SND.WND also can be already
@@ -93,7 +94,9 @@ static inline __u32 tcp_acceptable_seq(const struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 
-	if (!before(tcp_wnd_end(tp), tp->snd_nxt))
+	if (!before(tcp_wnd_end(tp), tp->snd_nxt) ||
+	    (tp->rx_opt.wscale_ok &&
+	     ((tp->snd_nxt - tcp_wnd_end(tp)) < (1 << tp->rx_opt.rcv_wscale))))
 		return tp->snd_nxt;
 	else
 		return tcp_wnd_end(tp);