diff --git a/sys/netinet/sctp_usrreq.c b/sys/netinet/sctp_usrreq.c
index add1c95273c4..a70ccbcf2ca6 100644
--- a/sys/netinet/sctp_usrreq.c
+++ b/sys/netinet/sctp_usrreq.c
@@ -152,7 +152,7 @@ sctp_notify(struct sctp_inpcb *inp,
     uint8_t icmp_type,
     uint8_t icmp_code,
     uint16_t ip_len,
-    uint16_t next_mtu)
+    uint32_t next_mtu)
 {
 #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
 	struct socket *so;
@@ -328,7 +328,7 @@ sctp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 			    icmp->icmp_type,
 			    icmp->icmp_code,
 			    ntohs(inner_ip->ip_len),
-			    ntohs(icmp->icmp_nextmtu));
+			    (uint32_t)ntohs(icmp->icmp_nextmtu));
 		} else {
 			if ((stcb == NULL) && (inp != NULL)) {
 				/* reduce ref-count */
diff --git a/sys/netinet/sctp_var.h b/sys/netinet/sctp_var.h
index 6365dfec1c8c..9e149e681386 100644
--- a/sys/netinet/sctp_var.h
+++ b/sys/netinet/sctp_var.h
@@ -341,7 +341,7 @@ void sctp_drain(void);
 void sctp_init(void);
 void 
 sctp_notify(struct sctp_inpcb *, struct sctp_tcb *, struct sctp_nets *,
-    uint8_t, uint8_t, uint16_t, uint16_t);
+    uint8_t, uint8_t, uint16_t, uint32_t);
 int sctp_flush(struct socket *, int);
 int sctp_shutdown(struct socket *);
 int 
diff --git a/sys/netinet/sctputil.c b/sys/netinet/sctputil.c
index 1b5173167eed..2951ad686145 100644
--- a/sys/netinet/sctputil.c
+++ b/sys/netinet/sctputil.c
@@ -6971,7 +6971,7 @@ sctp_recv_icmp_tunneled_packet(int cmd, struct sockaddr *sa, void *vip, void *ct
 		}
 		sctp_notify(inp, stcb, net, type, code,
 		    ntohs(inner_ip->ip_len),
-		    ntohs(icmp->icmp_nextmtu));
+		    (uint32_t)ntohs(icmp->icmp_nextmtu));
 	} else {
 		if ((stcb == NULL) && (inp != NULL)) {
 			/* reduce ref-count */
@@ -7113,7 +7113,7 @@ sctp_recv_icmp6_tunneled_packet(int cmd, struct sockaddr *sa, void *d, void *ctx
 			code = ICMP6_PARAMPROB_NEXTHEADER;
 		}
 		sctp6_notify(inp, stcb, net, type, code,
-		    (uint16_t)ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
+		    ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
 	} else {
 		if ((stcb == NULL) && (inp != NULL)) {
 			/* reduce inp's ref-count */
diff --git a/sys/netinet6/sctp6_usrreq.c b/sys/netinet6/sctp6_usrreq.c
index c2a45a661333..02310c9eb7bc 100644
--- a/sys/netinet6/sctp6_usrreq.c
+++ b/sys/netinet6/sctp6_usrreq.c
@@ -183,7 +183,7 @@ sctp6_notify(struct sctp_inpcb *inp,
     struct sctp_nets *net,
     uint8_t icmp6_type,
     uint8_t icmp6_code,
-    uint16_t next_mtu)
+    uint32_t next_mtu)
 {
 #if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
 	struct socket *so;
@@ -383,7 +383,7 @@ sctp6_ctlinput(int cmd, struct sockaddr *pktdst, void *d)
 			sctp6_notify(inp, stcb, net,
 			    ip6cp->ip6c_icmp6->icmp6_type,
 			    ip6cp->ip6c_icmp6->icmp6_code,
-			    (uint16_t)ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
+			    ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
 		} else {
 			if ((stcb == NULL) && (inp != NULL)) {
 				/* reduce inp's ref-count */
diff --git a/sys/netinet6/sctp6_var.h b/sys/netinet6/sctp6_var.h
index 232fee15da1d..a24ceba7ee15 100644
--- a/sys/netinet6/sctp6_var.h
+++ b/sys/netinet6/sctp6_var.h
@@ -49,6 +49,6 @@ sctp6_output(struct sctp_inpcb *, struct mbuf *, struct sockaddr *,
 void sctp6_ctlinput(int, struct sockaddr *, void *);
 void 
 sctp6_notify(struct sctp_inpcb *, struct sctp_tcb *, struct sctp_nets *,
-    uint8_t, uint8_t, uint16_t);
+    uint8_t, uint8_t, uint32_t);
 #endif
 #endif