diff --git a/sys/netinet/sctp_header.h b/sys/netinet/sctp_header.h
index 4d5b5bc9db0..93dda17ae9b 100644
--- a/sys/netinet/sctp_header.h
+++ b/sys/netinet/sctp_header.h
@@ -180,7 +180,7 @@ struct sctp_init {
 }         SCTP_PACKED;
 #define SCTP_IDENTIFICATION_SIZE 16
 #define SCTP_ADDRESS_SIZE 4
-#define SCTP_RESERVE_SPACE 6
+#define SCTP_RESERVE_SPACE 5
 /* state cookie header */
 struct sctp_state_cookie {	/* this is our definition... */
 	uint8_t identification[SCTP_IDENTIFICATION_SIZE];	/* id of who we are */
@@ -207,6 +207,7 @@ struct sctp_state_cookie {	/* this is our definition... */
 
 	uint8_t ipv4_scope;	/* IPv4 private addr scope */
 	uint8_t loopback_scope;	/* loopback scope information */
+	uint8_t zero_checksum;	/* copy of the inp value */
 	uint8_t reserved[SCTP_RESERVE_SPACE];	/* Align to 64 bits */
 	/*
 	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c
index dfc74e1e84f..6299c5c7d82 100644
--- a/sys/netinet/sctp_input.c
+++ b/sys/netinet/sctp_input.c
@@ -1880,6 +1880,7 @@ sctp_process_cookie_existing(struct mbuf *m, int iphlen, int offset,
 			}
 			SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_asconf_ack), aack);
 		}
+		asoc->zero_checksum = cookie->zero_checksum;
 
 		/* process the INIT-ACK info (my info) */
 		asoc->my_vtag = ntohl(initack_cp->init.initiate_tag);
@@ -2076,6 +2077,7 @@ sctp_process_cookie_new(struct mbuf *m, int iphlen, int offset,
 		    SCTP_FROM_SCTP_INPUT + SCTP_LOC_18);
 		return (NULL);
 	}
+	asoc->zero_checksum = cookie->zero_checksum;
 	/* process the INIT-ACK info (my info) */
 	asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);
 
diff --git a/sys/netinet/sctp_output.c b/sys/netinet/sctp_output.c
index 97e89cb1396..2ce05336482 100644
--- a/sys/netinet/sctp_output.c
+++ b/sys/netinet/sctp_output.c
@@ -5804,6 +5804,11 @@ do_a_abort:
 #endif
 		}
 	}
+	if (asoc != NULL) {
+		stc.zero_checksum = asoc->zero_checksum > 0 ? 1 : 0;
+	} else {
+		stc.zero_checksum = inp->zero_checksum;
+	}
 	/* Now lets put the SCTP header in place */
 	initack = mtod(m, struct sctp_init_ack_chunk *);
 	/* Save it off for quick ref */