diff --git a/sys/dev/xen/netback/netback.c b/sys/dev/xen/netback/netback.c
index a6111e265f5..3088ecbdd12 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 a2caef54a30..6c48b5b89d6 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -234,7 +234,7 @@ 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 0eb4673a038..65ec49eb5a4 100644
--- a/sys/netinet/ip_ipsec.c
+++ b/sys/netinet/ip_ipsec.c
@@ -343,7 +343,7 @@ 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 00c3c3ceacf..a10976a06b6 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -589,7 +589,7 @@ passout:
 	}
 #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
@@ -731,7 +731,7 @@ 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 aeb97153855..d9ae238835f 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 44196b16abe..e66815ee517 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 c2ec49aa350..a878aacf79f 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_inet.h"
 #include "opt_inet6.h"
 #include "opt_ipsec.h"
+#include "opt_sctp.h"
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -102,6 +103,10 @@ __FBSDID("$FreeBSD$");
 #include <netipsec/key.h>
 #include <netinet6/ip6_ipsec.h>
 #endif /* IPSEC */
+#ifdef SCTP
+#include <netinet/sctp.h>
+#include <netinet/sctp_crc32.h>
+#endif
 
 #include <netinet6/ip6protosw.h>
 #include <netinet6/scope6_var.h>
@@ -208,6 +213,9 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 	struct route_in6 *ro_pmtu = NULL;
 	int hdrsplit = 0;
 	int needipsec = 0;
+#ifdef SCTP
+	int sw_csum;
+#endif
 #ifdef IPSEC
 	struct ipsec_output_state state;
 	struct ip6_rthdr *rh = NULL;
@@ -829,6 +837,10 @@ again:
 			}
 			m->m_pkthdr.csum_flags |=
 			    CSUM_IP_CHECKED | CSUM_IP_VALID;
+#ifdef SCTP
+			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
+				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
+#endif
 			error = netisr_queue(NETISR_IPV6, m);
 			goto done;
 		} else
@@ -857,6 +869,13 @@ passout:
 	 * 4: if dontfrag == 1 && alwaysfrag == 1
 	 *	error, as we cannot handle this conflicting request
 	 */
+#ifdef SCTP
+	sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
+	if (sw_csum & CSUM_SCTP) {
+		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
+		sw_csum &= ~CSUM_SCTP;
+	}
+#endif
 	tlen = m->m_pkthdr.len;
 
 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))