Index: sys/net/pfvar.h
===================================================================
--- sys/net/pfvar.h
+++ sys/net/pfvar.h
@@ -154,6 +154,8 @@
 #define	PF_RULES_RASSERT()	rw_assert(&pf_rules_lock, RA_RLOCKED)
 #define	PF_RULES_WASSERT()	rw_assert(&pf_rules_lock, RA_WLOCKED)
 
+extern struct sx pf_end_lock;
+
 #define	PF_MODVER	1
 #define	PFLOG_MODVER	1
 #define	PFSYNC_MODVER	1
Index: sys/netpfil/pf/pf.c
===================================================================
--- sys/netpfil/pf/pf.c
+++ sys/netpfil/pf/pf.c
@@ -1428,8 +1428,9 @@
 	VNET_ITERATOR_DECL(vnet_iter);
 	u_int idx = 0;
 
+	sx_xlock(&pf_end_lock);
 	for (;;) {
-		tsleep(pf_purge_thread, 0, "pftm", hz / 10);
+		sx_sleep(pf_purge_thread, &pf_end_lock, 0, "pftm", hz / 10);
 
 		VNET_LIST_RLOCK();
 		VNET_FOREACH(vnet_iter) {
@@ -1438,6 +1439,7 @@
 			if (pf_end_threads) {
 				pf_end_threads++;
 				wakeup(pf_purge_thread);
+				sx_xunlock(&pf_end_lock);
 				VNET_LIST_RUNLOCK();
 				kproc_exit(0);
 			}
Index: sys/netpfil/pf/pf_ioctl.c
===================================================================
--- sys/netpfil/pf/pf_ioctl.c
+++ sys/netpfil/pf/pf_ioctl.c
@@ -201,6 +201,7 @@
 
 struct rwlock			pf_rules_lock;
 struct sx			pf_ioctl_lock;
+struct sx			pf_end_lock;
 
 /* pfsync */
 pfsync_state_import_t 		*pfsync_state_import_ptr = NULL;
@@ -3730,6 +3731,7 @@
 
 	rw_init(&pf_rules_lock, "pf rulesets");
 	sx_init(&pf_ioctl_lock, "pf ioctl");
+	sx_init(&pf_end_lock, "pf end thread");
 
 	pf_mtag_initialize();
 
@@ -3791,11 +3793,13 @@
 	/* Unload the root VNET */
 	pf_unload_vnet();
 
+	sx_xlock(&pf_end_lock);
 	pf_end_threads = 1;
 	while (pf_end_threads < 2) {
 		wakeup_one(pf_purge_thread);
-		tsleep(pf_purge_thread, 0, "pftmo", 0);
+		sx_sleep(pf_purge_thread, &pf_end_lock, 0, "pftmo", 0);
 	}
+	sx_xunlock(&pf_end_lock);
 
 	if (pf_dev != NULL)
 		destroy_dev(pf_dev);
@@ -3804,6 +3808,7 @@
 
 	rw_destroy(&pf_rules_lock);
 	sx_destroy(&pf_ioctl_lock);
+	sx_destroy(&pf_end_lock);
 
 	return (error);
 }