diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -517,6 +517,22 @@
 		m_copyback(m, off, sizeof(*uh), (caddr_t)uh);
 		break;
 	}
+	case IPPROTO_SCTP: {
+		struct sctphdr *sh = &pd->hdr.sctp;
+		uint16_t checksum = 0;
+
+		if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af))
+			pf_change_ap(m, pd->src, &sh->src_port, pd->ip_sum,
+			    &checksum, &nk->addr[pd->sidx],
+			    nk->port[pd->sidx], 1, pd->af);
+		if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af))
+			pf_change_ap(m, pd->dst, &sh->dest_port, pd->ip_sum,
+			    &checksum, &nk->addr[pd->didx],
+			    nk->port[pd->didx], 1, pd->af);
+		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
+		m_copyback(m, off, sizeof(*sh), (caddr_t)sh);
+		break;
+	}
 	case IPPROTO_ICMP: {
 		struct icmp *ih = &pd->hdr.icmp;
 
@@ -4453,6 +4469,37 @@
 			}
 			rewrite++;
 			break;
+		case IPPROTO_SCTP: {
+			uint16_t checksum = 0;
+
+			if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
+			    nk->port[pd->sidx] != sport) {
+				pf_change_ap(m, saddr, &pd->hdr.sctp.src_port,
+				    pd->ip_sum, &checksum,
+				    &nk->addr[pd->sidx],
+				    nk->port[pd->sidx], 1, af);
+				sport = pd->hdr.sctp.src_port;
+				pd->sport = &pd->hdr.sctp.src_port;
+			}
+			if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
+			    nk->port[pd->didx] != dport) {
+				pf_change_ap(m, daddr, &pd->hdr.sctp.dest_port,
+				    pd->ip_sum, &checksum,
+				    &nk->addr[pd->didx],
+				    nk->port[pd->didx], 1, af);
+				dport = pd->hdr.sctp.dest_port;
+				pd->dport = &pd->hdr.sctp.dest_port;
+			}
+
+			/* We can't do an incremental update, because
+			 * it's CRC32 and we may do futher
+			 * modifications later, so let the output path
+			 * recompute the checksum. */
+			m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
+
+			rewrite++;
+			break;
+		}
 #ifdef INET
 		case IPPROTO_ICMP:
 			nk->port[0] = nk->port[1];
@@ -5847,6 +5894,29 @@
 
 	(*state)->expire = time_uptime;
 
+	/* translate source/destination address, if necessary */
+	if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
+		uint16_t checksum = 0;
+		struct pf_state_key *nk = (*state)->key[pd->didx];
+
+		if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
+		    nk->port[pd->sidx] != pd->hdr.sctp.src_port)
+			pf_change_ap(m, pd->src, &pd->hdr.sctp.src_port,
+			    pd->ip_sum, &checksum, &nk->addr[pd->sidx],
+			    nk->port[pd->sidx], 1, pd->af);
+
+		if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
+		    nk->port[pd->didx] != pd->hdr.sctp.dest_port)
+			pf_change_ap(m, pd->dst, &pd->hdr.sctp.dest_port,
+			    pd->ip_sum, &checksum, &nk->addr[pd->didx],
+			    nk->port[pd->didx], 1, pd->af);
+
+		/* Force checksum recalculation. */
+		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
+
+		m_copyback(m, off, sizeof(pd->hdr.sctp), (caddr_t)&pd->hdr.sctp);
+	}
+
 	return (PF_PASS);
 }