diff --git a/sys/dev/xen/netback/netback.c b/sys/dev/xen/netback/netback.c
index a6111e265f58..3088ecbdd120 100644
--- a/sys/dev/xen/netback/netback.c
+++ b/sys/dev/xen/netback/netback.c
@@ -302,7 +302,7 @@ fixup_checksum(struct mbuf *m)
 		m->m_pkthdr.csum_flags &= ~CSUM_TCP;
 #ifdef SCTP
 	} else if (sw_csum & CSUM_SCTP) {
-		sctp_delayed_cksum(m);
+		sctp_delayed_cksum(m, iphlen);
 		sw_csum &= ~CSUM_SCTP;
 #endif
 	} else {
diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c
index 7fd20f84527c..22e52bafbf2b 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -227,7 +227,7 @@ divert_packet(struct mbuf *m, int incoming)
 #ifdef SCTP
 	if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
 		ip->ip_len = ntohs(ip->ip_len);
-		sctp_delayed_cksum(m);
+		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 		ip->ip_len = htons(ip->ip_len);
 	}
diff --git a/sys/netinet/ip_ipsec.c b/sys/netinet/ip_ipsec.c
index b49b620f3976..3465d4b5f5b5 100644
--- a/sys/netinet/ip_ipsec.c
+++ b/sys/netinet/ip_ipsec.c
@@ -342,7 +342,7 @@ ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error)
 		}
 #ifdef SCTP
 		if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP) {
-			sctp_delayed_cksum(*m);
+			sctp_delayed_cksum(*m, (uint32_t)(ip->ip_hl << 2));
 			(*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 		}
 #endif
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index ca5de12384f3..dc26705bd217 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -583,7 +583,7 @@ ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 	}
 #ifdef SCTP
 	if (sw_csum & CSUM_SCTP) {
-		sctp_delayed_cksum(m);
+		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
 		sw_csum &= ~CSUM_SCTP;
 	}
 #endif
@@ -725,7 +725,7 @@ ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 #ifdef SCTP
 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP &&
 	    (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
-		sctp_delayed_cksum(m0);
+		sctp_delayed_cksum(m0, hlen);
 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 	}
 #endif
diff --git a/sys/netinet/sctp_crc32.c b/sys/netinet/sctp_crc32.c
index aeb97153855c..d9ae238835f1 100644
--- a/sys/netinet/sctp_crc32.c
+++ b/sys/netinet/sctp_crc32.c
@@ -127,14 +127,12 @@ sctp_calculate_cksum(struct mbuf *m, uint32_t offset)
 
 
 void
-sctp_delayed_cksum(struct mbuf *m)
+sctp_delayed_cksum(struct mbuf *m, uint32_t offset)
 {
 	struct ip *ip;
 	uint32_t checksum;
-	uint32_t offset;
 
 	ip = mtod(m, struct ip *);
-	offset = ip->ip_hl << 2;
 	checksum = sctp_calculate_cksum(m, offset);
 	SCTP_STAT_DECR(sctps_sendhwcrc);
 	SCTP_STAT_INCR(sctps_sendswcrc);
diff --git a/sys/netinet/sctp_crc32.h b/sys/netinet/sctp_crc32.h
index 44196b16abec..e66815ee5172 100644
--- a/sys/netinet/sctp_crc32.h
+++ b/sys/netinet/sctp_crc32.h
@@ -39,7 +39,7 @@ __FBSDID("$FreeBSD$");
 #if defined(_KERNEL) || defined(__Userspace__)
 
 uint32_t sctp_calculate_cksum(struct mbuf *, uint32_t);
-void sctp_delayed_cksum(struct mbuf *);
+void sctp_delayed_cksum(struct mbuf *, uint32_t offset);
 
 #endif				/* _KERNEL */
 
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index aadb51fd760a..a878aacf79ff 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -872,7 +872,7 @@ skip_ipsec2:;
 #ifdef SCTP
 	sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
 	if (sw_csum & CSUM_SCTP) {
-		sctp_delayed_cksum(m);
+		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 		sw_csum &= ~CSUM_SCTP;
 	}
 #endif