diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 78bfadfcf342695ed2e7f02626ddd1fda7d4d543..8b5ba0a5cd38608b55313d6721719d2d0ef6b055 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -403,6 +403,8 @@ static void hystart_update(struct sock *sk, u32 delay)
 
 	if (hystart_detect & HYSTART_DELAY) {
 		/* obtain the minimum delay of more than sampling packets */
+		if (ca->curr_rtt > delay)
+			ca->curr_rtt = delay;
 		if (ca->sample_cnt < HYSTART_MIN_SAMPLES) {
 			if (ca->curr_rtt == 0 || ca->curr_rtt > delay)
 				ca->curr_rtt = delay;