diff --git a/sys/netpfil/ipfw/ip_fw2.c b/sys/netpfil/ipfw/ip_fw2.c
--- a/sys/netpfil/ipfw/ip_fw2.c
+++ b/sys/netpfil/ipfw/ip_fw2.c
@@ -69,6 +69,7 @@
 #include <net/route/nhop.h>
 #include <net/pfil.h>
 #include <net/vnet.h>
+#include <net/if_pfsync.h>
 
 #include <netpfil/pf/pf_mtag.h>
 
@@ -1718,6 +1719,10 @@
 				PULLUP_TO(hlen, ulp, struct ip);
 				break;
 
+			case IPPROTO_PFSYNC:
+				PULLUP_TO(hlen, ulp, struct pfsync_header);
+				break;
+
 			default:
 				if (V_fw_verbose)
 					printf("IPFW2: IPV6 - Unknown "