diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 688b95594f2e..3c24881f2a65 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -943,7 +943,8 @@ static void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
 		if (tp->packets_out > tp->snd_cwnd_used)
 			tp->snd_cwnd_used = tp->packets_out;
 
-		if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
+		if (sysctl_tcp_slow_start_after_idle &&
+		    (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
 			tcp_cwnd_application_limited(sk);
 	}
 }