diff --git a/sys/netinet/sctp_usrreq.c b/sys/netinet/sctp_usrreq.c
index a70ccbcf2ca6..b433df57a594 100644
--- a/sys/netinet/sctp_usrreq.c
+++ b/sys/netinet/sctp_usrreq.c
@@ -220,11 +220,11 @@ sctp_notify(struct sctp_inpcb *inp,
 			timer_stopped = 0;
 		}
 		/* Update the path MTU. */
+		if (net->port) {
+			next_mtu -= sizeof(struct udphdr);
+		}
 		if (net->mtu > next_mtu) {
 			net->mtu = next_mtu;
-			if (net->port) {
-				net->mtu -= sizeof(struct udphdr);
-			}
 		}
 		/* Update the association MTU */
 		if (stcb->asoc.smallest_mtu > next_mtu) {
diff --git a/sys/netinet6/sctp6_usrreq.c b/sys/netinet6/sctp6_usrreq.c
index 02310c9eb7bc..054b4c1b06a5 100644
--- a/sys/netinet6/sctp6_usrreq.c
+++ b/sys/netinet6/sctp6_usrreq.c
@@ -237,11 +237,11 @@ sctp6_notify(struct sctp_inpcb *inp,
 			timer_stopped = 0;
 		}
 		/* Update the path MTU. */
+		if (net->port) {
+			next_mtu -= sizeof(struct udphdr);
+		}
 		if (net->mtu > next_mtu) {
 			net->mtu = next_mtu;
-			if (net->port) {
-				net->mtu -= sizeof(struct udphdr);
-			}
 		}
 		/* Update the association MTU */
 		if (stcb->asoc.smallest_mtu > next_mtu) {