diff --git a/sys/netinet/cc/cc_cubic.c b/sys/netinet/cc/cc_cubic.c
index 0e0f2e57e92bcc..033fac9b80dc61 100644
--- a/sys/netinet/cc/cc_cubic.c
+++ b/sys/netinet/cc/cc_cubic.c
@@ -324,7 +324,12 @@ cubic_post_recovery(struct cc_var *ccv)
 			pipe = CCV(ccv, snd_max) - ccv->curack;
 
 		if (pipe < CCV(ccv, snd_ssthresh))
-			CCV(ccv, snd_cwnd) = pipe + CCV(ccv, t_maxseg);
+			/*
+			 * Ensure that cwnd does not collapse to 1 MSS under
+			 * adverse conditions. Implements RFC6582
+			 */
+			CCV(ccv, snd_cwnd) = max(pipe, CCV(ccv, t_maxseg)) +
+			    CCV(ccv, t_maxseg);
 		else
 			/* Update cwnd based on beta and adjusted max_cwnd. */
 			CCV(ccv, snd_cwnd) = max(1, ((CUBIC_BETA *
diff --git a/sys/netinet/cc/cc_htcp.c b/sys/netinet/cc/cc_htcp.c
index 30962485a3e7ae..1686a4e5553a6c 100644
--- a/sys/netinet/cc/cc_htcp.c
+++ b/sys/netinet/cc/cc_htcp.c
@@ -366,7 +366,12 @@ htcp_post_recovery(struct cc_var *ccv)
 			pipe = CCV(ccv, snd_max) - ccv->curack;
 		
 		if (pipe < CCV(ccv, snd_ssthresh))
-			CCV(ccv, snd_cwnd) = pipe + CCV(ccv, t_maxseg);
+			/*
+			 * Ensure that cwnd down not collape to 1 MSS under
+			 * adverse conditions. Implements RFC6582
+			 */
+			CCV(ccv, snd_cwnd) = max(pipe, CCV(ccv, t_maxseg)) +
+			    CCV(ccv, t_maxseg);
 		else
 			CCV(ccv, snd_cwnd) = max(1, ((htcp_data->beta *
 			    htcp_data->prev_cwnd / CCV(ccv, t_maxseg))
diff --git a/sys/netinet/cc/cc_newreno.c b/sys/netinet/cc/cc_newreno.c
index 50c0b79660e220..102cfed741e884 100644
--- a/sys/netinet/cc/cc_newreno.c
+++ b/sys/netinet/cc/cc_newreno.c
@@ -295,7 +295,12 @@ newreno_post_recovery(struct cc_var *ccv)
 			pipe = CCV(ccv, snd_max) - ccv->curack;
 
 		if (pipe < CCV(ccv, snd_ssthresh))
-			CCV(ccv, snd_cwnd) = pipe + CCV(ccv, t_maxseg);
+			/*
+			 * Ensure that cwnd does not collapse to 1 MSS under
+			 * adverse conditons. Implements RFC6582
+			 */
+			CCV(ccv, snd_cwnd) = max(pipe, CCV(ccv, t_maxseg)) +
+			    CCV(ccv, t_maxseg);
 		else
 			CCV(ccv, snd_cwnd) = CCV(ccv, snd_ssthresh);
 	}