diff --git a/include/net/tcp.h b/include/net/tcp.h
index f1f4727..de88c54 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -632,7 +632,7 @@
 	/* return slow start threshold (required) */
 	u32 (*ssthresh)(struct sock *sk);
 	/* lower bound for congestion window (optional) */
-	u32 (*min_cwnd)(struct sock *sk);
+	u32 (*min_cwnd)(const struct sock *sk);
 	/* do new cwnd calculation (required) */
 	void (*cong_avoid)(struct sock *sk, u32 ack,
 			   u32 rtt, u32 in_flight, int good_ack);
@@ -667,7 +667,7 @@
 extern u32 tcp_reno_ssthresh(struct sock *sk);
 extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack,
 				u32 rtt, u32 in_flight, int flag);
-extern u32 tcp_reno_min_cwnd(struct sock *sk);
+extern u32 tcp_reno_min_cwnd(const struct sock *sk);
 extern struct tcp_congestion_ops tcp_reno;
 
 static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index 035f209..b2d9021 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -198,12 +198,6 @@
 	return max(tp->snd_cwnd, ca->last_max_cwnd);
 }
 
-static u32 bictcp_min_cwnd(struct sock *sk)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-	return tp->snd_ssthresh;
-}
-
 static void bictcp_state(struct sock *sk, u8 new_state)
 {
 	if (new_state == TCP_CA_Loss)
@@ -231,7 +225,6 @@
 	.cong_avoid	= bictcp_cong_avoid,
 	.set_state	= bictcp_state,
 	.undo_cwnd	= bictcp_undo_cwnd,
-	.min_cwnd	= bictcp_min_cwnd,
 	.pkts_acked     = bictcp_acked,
 	.owner		= THIS_MODULE,
 	.name		= "bic",
diff --git a/net/ipv4/tcp_compound.c b/net/ipv4/tcp_compound.c
index ec68cb8..bc54f7e 100644
--- a/net/ipv4/tcp_compound.c
+++ b/net/ipv4/tcp_compound.c
@@ -419,7 +419,6 @@
 	.init		= tcp_compound_init,
 	.ssthresh	= tcp_reno_ssthresh,
 	.cong_avoid	= tcp_compound_cong_avoid,
-	.min_cwnd	= tcp_reno_min_cwnd,
 	.rtt_sample	= tcp_compound_rtt_calc,
 	.set_state	= tcp_compound_state,
 	.cwnd_event	= tcp_compound_cwnd_event,
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 91c2f41..857eefc 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -38,7 +38,7 @@
 	int ret = 0;
 
 	/* all algorithms must implement ssthresh and cong_avoid ops */
-	if (!ca->ssthresh || !ca->cong_avoid || !ca->min_cwnd) {
+	if (!ca->ssthresh || !ca->cong_avoid) {
 		printk(KERN_ERR "TCP %s does not implement required ops\n",
 		       ca->name);
 		return -EINVAL;
@@ -251,8 +251,8 @@
 }
 EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
 
-/* Lower bound on congestion window. */
-u32 tcp_reno_min_cwnd(struct sock *sk)
+/* Lower bound on congestion window with halving. */
+u32 tcp_reno_min_cwnd(const struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	return tp->snd_ssthresh/2;
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 31a4986..78b7a6b 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -325,11 +325,6 @@
 	return max(tcp_sk(sk)->snd_cwnd, ca->last_max_cwnd);
 }
 
-static u32 bictcp_min_cwnd(struct sock *sk)
-{
-	return tcp_sk(sk)->snd_ssthresh;
-}
-
 static void bictcp_state(struct sock *sk, u8 new_state)
 {
 	if (new_state == TCP_CA_Loss)
@@ -357,7 +352,6 @@
 	.cong_avoid	= bictcp_cong_avoid,
 	.set_state	= bictcp_state,
 	.undo_cwnd	= bictcp_undo_cwnd,
-	.min_cwnd	= bictcp_min_cwnd,
 	.pkts_acked     = bictcp_acked,
 	.owner		= THIS_MODULE,
 	.name		= "cubic",
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
index 1b2ff53..3d92c18 100644
--- a/net/ipv4/tcp_htcp.c
+++ b/net/ipv4/tcp_htcp.c
@@ -246,14 +246,6 @@
 	}
 }
 
-/* Lower bound on congestion window. */
-static u32 htcp_min_cwnd(struct sock *sk)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-	return tp->snd_ssthresh;
-}
-
-
 static void htcp_init(struct sock *sk)
 {
 	struct htcp *ca = inet_csk_ca(sk);
@@ -285,7 +277,6 @@
 static struct tcp_congestion_ops htcp = {
 	.init		= htcp_init,
 	.ssthresh	= htcp_recalc_ssthresh,
-	.min_cwnd	= htcp_min_cwnd,
 	.cong_avoid	= htcp_cong_avoid,
 	.set_state	= htcp_state,
 	.undo_cwnd	= htcp_cwnd_undo,
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6d16788..e08245b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1689,17 +1689,26 @@
 	tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
+/* Lower bound on congestion window is slow start threshold
+ * unless congestion avoidance choice decides to overide it.
+ */
+static inline u32 tcp_cwnd_min(const struct sock *sk)
+{
+	const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops;
+
+	return ca_ops->min_cwnd ? ca_ops->min_cwnd(sk) : tcp_sk(sk)->snd_ssthresh;
+}
+
 /* Decrease cwnd each second ack. */
 static void tcp_cwnd_down(struct sock *sk)
 {
-	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	int decr = tp->snd_cwnd_cnt + 1;
 
 	tp->snd_cwnd_cnt = decr&1;
 	decr >>= 1;
 
-	if (decr && tp->snd_cwnd > icsk->icsk_ca_ops->min_cwnd(sk))
+	if (decr && tp->snd_cwnd > tcp_cwnd_min(sk))
 		tp->snd_cwnd -= decr;
 
 	tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp)+1);
diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
index 1091671..11b42a7 100644
--- a/net/ipv4/tcp_veno.c
+++ b/net/ipv4/tcp_veno.c
@@ -199,17 +199,10 @@
 		return max(tp->snd_cwnd >> 1U, 2U);
 }
 
-static u32 tcp_veno_min_cwnd(struct sock * sk)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-	return tp->snd_ssthresh;
-}
-
 static struct tcp_congestion_ops tcp_veno = {
 	.init		= tcp_veno_init,
 	.ssthresh	= tcp_veno_ssthresh,
 	.cong_avoid	= tcp_veno_cong_avoid,
-	.min_cwnd 	= tcp_veno_min_cwnd,
 	.rtt_sample	= tcp_veno_rtt_calc,
 	.set_state	= tcp_veno_state,
 	.cwnd_event	= tcp_veno_cwnd_event,
diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
index 0c340c3..29eb258 100644
--- a/net/ipv4/tcp_westwood.c
+++ b/net/ipv4/tcp_westwood.c
@@ -162,12 +162,6 @@
 	return w->cumul_ack;
 }
 
-static inline u32 westwood_bw_rttmin(const struct sock *sk)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-	const struct westwood *w = inet_csk_ca(sk);
-	return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2);
-}
 
 /*
  * TCP Westwood
@@ -175,9 +169,11 @@
  * in packets we use mss_cache). Rttmin is guaranteed to be >= 2
  * so avoids ever returning 0.
  */
-static u32 tcp_westwood_cwnd_min(struct sock *sk)
+static u32 tcp_westwood_bw_rttmin(const struct sock *sk)
 {
-	return westwood_bw_rttmin(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct westwood *w = inet_csk_ca(sk);
+	return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2);
 }
 
 static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event)
@@ -191,11 +187,11 @@
 		break;
 
 	case CA_EVENT_COMPLETE_CWR:
-		tp->snd_cwnd = tp->snd_ssthresh = westwood_bw_rttmin(sk);
+		tp->snd_cwnd = tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk);
 		break;
 
 	case CA_EVENT_FRTO:
-		tp->snd_ssthresh = westwood_bw_rttmin(sk);
+		tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk);
 		break;
 
 	case CA_EVENT_SLOW_ACK:
@@ -235,7 +231,7 @@
 	.init		= tcp_westwood_init,
 	.ssthresh	= tcp_reno_ssthresh,
 	.cong_avoid	= tcp_reno_cong_avoid,
-	.min_cwnd	= tcp_westwood_cwnd_min,
+	.min_cwnd	= tcp_westwood_bw_rttmin,
 	.cwnd_event	= tcp_westwood_event,
 	.get_info	= tcp_westwood_info,
 	.pkts_acked	= tcp_westwood_pkts_acked,