diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 3e0d196..5b6690d0 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -295,7 +295,9 @@ static u16 tcp_select_window(struct sock *sk)
 	/* RFC1323 scaling applied */
 	new_win >>= tp->rx_opt.rcv_wscale;
 
+	/* If we advertise zero window, disable fast path. */
 	if (new_win == 0) {
+		tp->pred_flags = 0;
 		if (old_win)
 			NET_INC_STATS(sock_net(sk),
 				      LINUX_MIB_TCPTOZEROWINDOWADV);