diff --git a/sbin/ifconfig/ifpfsync.c b/sbin/ifconfig/ifpfsync.c
--- a/sbin/ifconfig/ifpfsync.c
+++ b/sbin/ifconfig/ifpfsync.c
@@ -178,7 +178,7 @@
 	if (ioctl(s, SIOCGETPFSYNC, (caddr_t)&ifr) == -1)
 		err(1, "SIOCGETPFSYNC");
 
-	preq.pfsyncr_defer = d;
+	preq.pfsyncr_defer = d ? PFSYNCF_DEFER : 0;
 	if (ioctl(s, SIOCSETPFSYNC, (caddr_t)&ifr) == -1)
 		err(1, "SIOCSETPFSYNC");
 }
diff --git a/sys/netpfil/pf/if_pfsync.c b/sys/netpfil/pf/if_pfsync.c
--- a/sys/netpfil/pf/if_pfsync.c
+++ b/sys/netpfil/pf/if_pfsync.c
@@ -1399,7 +1399,7 @@
 			    pfsyncr.pfsyncr_syncpeer.s_addr;
 
 		sc->sc_maxupdates = pfsyncr.pfsyncr_maxupdates;
-		if (pfsyncr.pfsyncr_defer) {
+		if (pfsyncr.pfsyncr_defer & PFSYNCF_DEFER) {
 			sc->sc_flags |= PFSYNCF_DEFER;
 			V_pfsync_defer_ptr = pfsync_defer;
 		} else {