diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -3179,7 +3179,9 @@
 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
 			tp->t_flags |= TF_ACKNOW;
 		}
-		if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) {
+		if ((tp->t_flags & TF_SACK_PERMIT) &&
+		    (save_tlen > 0) &&
+		    TCPS_HAVEESTABLISHED(tp->t_state)) {
 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
 				/*
 				 * DSACK actually handled in the fastpath