diff --git a/usrsctplib/netinet/sctp.h b/usrsctplib/netinet/sctp.h
index 4a7c12d..ee5c0ba 100755
--- a/usrsctplib/netinet/sctp.h
+++ b/usrsctplib/netinet/sctp.h
@@ -1,3 +1,4 @@
+
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -34,7 +35,7 @@
 
 #ifdef __FreeBSD__
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/sys/netinet/sctp.h 345461 2019-03-23 22:56:03Z tuexen $");
+__FBSDID("$FreeBSD: head/sys/netinet/sctp.h 356270 2020-01-02 13:55:10Z tuexen $");
 #endif
 
 #ifndef _NETINET_SCTP_H_
@@ -609,7 +610,10 @@
 #define SCTP_MOBILITY_PRIM_DELETED       0x00000004
 
 
-#define SCTP_SMALLEST_PMTU 512	 /* smallest pmtu allowed when disabling PMTU discovery */
+/* Smallest PMTU allowed when disabling PMTU discovery */
+#define SCTP_SMALLEST_PMTU 512
+/* Largest PMTU allowed when disabling PMTU discovery */
+#define SCTP_LARGEST_PMTU  65536
 
 #if defined(__Userspace_os_Windows)
 #pragma pack(pop)
diff --git a/usrsctplib/netinet/sctp_usrreq.c b/usrsctplib/netinet/sctp_usrreq.c
index c10dabb..6a19f62 100755
--- a/usrsctplib/netinet/sctp_usrreq.c
+++ b/usrsctplib/netinet/sctp_usrreq.c
@@ -34,7 +34,7 @@
 
 #ifdef __FreeBSD__
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/sys/netinet/sctp_usrreq.c 355265 2019-12-01 17:35:36Z tuexen $");
+__FBSDID("$FreeBSD: head/sys/netinet/sctp_usrreq.c 356270 2020-01-02 13:55:10Z tuexen $");
 #endif
 
 #include <netinet/sctp_os.h>
@@ -6210,6 +6210,14 @@
 			SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_USRREQ, EINVAL);
 			return (EINVAL);
 		}
+		if ((paddrp->spp_flags & SPP_PMTUD_DISABLE) &&
+		    ((paddrp->spp_pathmtu < SCTP_SMALLEST_PMTU) ||
+		     (paddrp->spp_pathmtu > SCTP_LARGEST_PMTU))) {
+			if (stcb)
+				SCTP_TCB_UNLOCK(stcb);
+			SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_USRREQ, EINVAL);
+			return (EINVAL);
+		}
 
 		if (stcb != NULL) {
 			/************************TCB SPECIFIC SET ******************/
@@ -6241,7 +6249,7 @@
 						sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, inp, stcb, net);
 					}
 				}
-				if ((paddrp->spp_flags & SPP_PMTUD_DISABLE) && (paddrp->spp_pathmtu >= SCTP_SMALLEST_PMTU)) {
+				if (paddrp->spp_flags & SPP_PMTUD_DISABLE) {
 					if (SCTP_OS_TIMER_PENDING(&net->pmtu_timer.timer)) {
 						sctp_timer_stop(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, net,
 								SCTP_FROM_SCTP_USRREQ + SCTP_LOC_11);
@@ -6388,7 +6396,7 @@
 					}
 					sctp_stcb_feature_on(inp, stcb, SCTP_PCB_FLAGS_DONOT_HEARTBEAT);
 				}
-				if ((paddrp->spp_flags & SPP_PMTUD_DISABLE) && (paddrp->spp_pathmtu >= SCTP_SMALLEST_PMTU)) {
+				if (paddrp->spp_flags & SPP_PMTUD_DISABLE) {
 					TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
 						if (SCTP_OS_TIMER_PENDING(&net->pmtu_timer.timer)) {
 							sctp_timer_stop(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, net,
@@ -6491,9 +6499,7 @@
 					inp->sctp_ep.default_mtu = 0;
 					sctp_feature_off(inp, SCTP_PCB_FLAGS_DO_NOT_PMTUD);
 				} else if (paddrp->spp_flags & SPP_PMTUD_DISABLE) {
-					if (paddrp->spp_pathmtu >= SCTP_SMALLEST_PMTU) {
-						inp->sctp_ep.default_mtu = paddrp->spp_pathmtu;
-					}
+					inp->sctp_ep.default_mtu = paddrp->spp_pathmtu;
 					sctp_feature_on(inp, SCTP_PCB_FLAGS_DO_NOT_PMTUD);
 				}
 				if (paddrp->spp_flags & SPP_DSCP) {