Index: sys/net/pfvar.h
===================================================================
--- sys/net/pfvar.h
+++ sys/net/pfvar.h
@@ -1392,6 +1392,8 @@
 
 VNET_DECLARE(void *, pf_swi_cookie);
 #define V_pf_swi_cookie	VNET(pf_swi_cookie)
+VNET_DECLARE(struct intr_event *, pf_swi_ie);
+#define	V_pf_swi_ie	VNET(pf_swi_ie)
 
 VNET_DECLARE(uint64_t, pf_stateid[MAXCPU]);
 #define	V_pf_stateid	VNET(pf_stateid)
Index: sys/netpfil/pf/if_pfsync.c
===================================================================
--- sys/netpfil/pf/if_pfsync.c
+++ sys/netpfil/pf/if_pfsync.c
@@ -262,6 +262,8 @@
 #define	V_pfsyncif		VNET(pfsyncif)
 VNET_DEFINE_STATIC(void *, pfsync_swi_cookie) = NULL;
 #define	V_pfsync_swi_cookie	VNET(pfsync_swi_cookie)
+VNET_DEFINE_STATIC(struct intr_event *, pfsync_swi_ie);
+#define	V_pfsync_swi_ie		VNET(pfsync_swi_ie)
 VNET_DEFINE_STATIC(struct pfsyncstats, pfsyncstats);
 #define	V_pfsyncstats		VNET(pfsyncstats)
 VNET_DEFINE_STATIC(int, pfsync_carp_adj) = CARP_MAXSKEW;
@@ -2502,7 +2504,7 @@
 
 	V_pfsync_cloner = if_clone_simple(pfsyncname,
 	    pfsync_clone_create, pfsync_clone_destroy, 1);
-	error = swi_add(NULL, pfsyncname, pfsyncintr, V_pfsyncif,
+	error = swi_add(&V_pfsync_swi_ie, pfsyncname, pfsyncintr, V_pfsyncif,
 	    SWI_NET, INTR_MPSAFE, &V_pfsync_swi_cookie);
 	if (error) {
 		if_clone_detach(V_pfsync_cloner);
@@ -2517,11 +2519,15 @@
 static void
 vnet_pfsync_uninit(const void *unused __unused)
 {
+	int ret;
 
 	pfsync_pointers_uninit();
 
 	if_clone_detach(V_pfsync_cloner);
-	swi_remove(V_pfsync_swi_cookie);
+	ret = swi_remove(V_pfsync_swi_cookie);
+	MPASS(ret == 0);
+	ret = intr_event_destroy(V_pfsync_swi_ie);
+	MPASS(ret == 0);
 }
 
 VNET_SYSUNINIT(vnet_pfsync_uninit, SI_SUB_PROTO_FIREWALL, SI_ORDER_FOURTH,
Index: sys/netpfil/pf/pf.c
===================================================================
--- sys/netpfil/pf/pf.c
+++ sys/netpfil/pf/pf.c
@@ -395,6 +395,7 @@
     &pf_ioctl_maxcount, 0, "Maximum number of tables, addresses, ... in a single ioctl() call");
 
 VNET_DEFINE(void *, pf_swi_cookie);
+VNET_DEFINE(struct intr_event *, pf_swi_ie);
 
 VNET_DEFINE(uint32_t, pf_hashseed);
 #define	V_pf_hashseed	VNET(pf_hashseed)
Index: sys/netpfil/pf/pf_ioctl.c
===================================================================
--- sys/netpfil/pf/pf_ioctl.c
+++ sys/netpfil/pf/pf_ioctl.c
@@ -331,7 +331,7 @@
 	for (int i = 0; i < SCNT_MAX; i++)
 		V_pf_status.scounters[i] = counter_u64_alloc(M_WAITOK);
 
-	if (swi_add(NULL, "pf send", pf_intr, curvnet, SWI_NET,
+	if (swi_add(&V_pf_swi_ie, "pf send", pf_intr, curvnet, SWI_NET,
 	    INTR_MPSAFE, &V_pf_swi_cookie) != 0)
 		/* XXXGL: leaked all above. */
 		return;
@@ -4682,6 +4682,7 @@
 static void
 pf_unload_vnet(void)
 {
+	int ret;
 
 	V_pf_vnet_active = 0;
 	V_pf_status.running = 0;
@@ -4691,7 +4692,10 @@
 	shutdown_pf();
 	PF_RULES_WUNLOCK();
 
-	swi_remove(V_pf_swi_cookie);
+	ret = swi_remove(V_pf_swi_cookie);
+	MPASS(ret == 0);
+	ret = intr_event_destroy(V_pf_swi_ie);
+	MPASS(ret == 0);
 
 	pf_unload_vnet_purge();