diff --git a/share/man/man4/pf.4 b/share/man/man4/pf.4
--- a/share/man/man4/pf.4
+++ b/share/man/man4/pf.4
@@ -87,6 +87,10 @@
 Size of hash table that store source nodes.
 Should be power of 2.
 Default value is 32768.
+.It Va net.pf.default_to_drop
+This value overrides
+.Cd "options PF_DEFAULT_TO_DROP"
+from kernel configuration file.
 .El
 .Pp
 Read only
diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -199,6 +199,16 @@
     &VNET_NAME(pf_filter_local), false,
     "Enable filtering for packets delivered to local network stack");
 
+#ifdef PF_DEFAULT_TO_DROP
+VNET_DEFINE_STATIC(bool, default_to_drop) = true;
+#else
+VNET_DEFINE_STATIC(bool, default_to_drop);
+#endif
+#define	V_default_to_drop VNET(default_to_drop)
+SYSCTL_BOOL(_net_pf, OID_AUTO, default_to_drop, CTLFLAG_RDTUN | CTLFLAG_VNET,
+    &VNET_NAME(default_to_drop), false,
+    "Make the default rule drop all packets.");
+
 static void		 pf_init_tagset(struct pf_tagset *, unsigned int *,
 			    unsigned int);
 static void		 pf_cleanup_tagset(struct pf_tagset *);
@@ -335,11 +345,7 @@
 
 	/* default rule should never be garbage collected */
 	V_pf_default_rule.entries.tqe_prev = &V_pf_default_rule.entries.tqe_next;
-#ifdef PF_DEFAULT_TO_DROP
-	V_pf_default_rule.action = PF_DROP;
-#else
-	V_pf_default_rule.action = PF_PASS;
-#endif
+	V_pf_default_rule.action = V_default_to_drop ? PF_DROP : PF_PASS;
 	V_pf_default_rule.nr = -1;
 	V_pf_default_rule.rtableid = -1;