diff --git a/sys/netpfil/ipfw/ip_dn_io.c b/sys/netpfil/ipfw/ip_dn_io.c
--- a/sys/netpfil/ipfw/ip_dn_io.c
+++ b/sys/netpfil/ipfw/ip_dn_io.c
@@ -669,6 +669,11 @@
 		memset(&q, 0, sizeof(struct mq));
 		CURVNET_SET(vnet_iter);
 
+		if (! V_dn_cfg.init_done) {
+			CURVNET_RESTORE();
+			continue;
+		}
+
 		DN_BH_WLOCK();
 
 		/* Update number of lost(coalesced) ticks. */
diff --git a/sys/netpfil/ipfw/ip_dummynet.c b/sys/netpfil/ipfw/ip_dummynet.c
--- a/sys/netpfil/ipfw/ip_dummynet.c
+++ b/sys/netpfil/ipfw/ip_dummynet.c
@@ -2562,7 +2562,7 @@
 {
 	if (V_dn_cfg.init_done)
 		return;
-	V_dn_cfg.init_done = 1;
+
 	/* Set defaults here. MSVC does not accept initializers,
 	 * and this is also useful for vimages
 	 */
@@ -2601,6 +2601,8 @@
 
 	/* Initialize curr_time adjustment mechanics. */
 	getmicrouptime(&V_dn_cfg.prev_t);
+
+	V_dn_cfg.init_done = 1;
 }
 
 static void