Index: kern/kern_alq.c
===================================================================
--- kern/kern_alq.c	(revision 250136)
+++ kern/kern_alq.c	(working copy)
@@ -99,6 +99,7 @@
 static int ald_shutingdown = 0;
 struct thread *ald_thread;
 static struct proc *ald_proc;
+static eventhandler_tag alq_eventhandler_tag = NULL;
 
 #define	ALD_LOCK()	mtx_lock(&ald_mtx)
 #define	ALD_UNLOCK()	mtx_unlock(&ald_mtx)
@@ -194,8 +195,8 @@
 
 	ald_thread = FIRST_THREAD_IN_PROC(ald_proc);
 
-	EVENTHANDLER_REGISTER(shutdown_pre_sync, ald_shutdown, NULL,
-	    SHUTDOWN_PRI_FIRST);
+	alq_eventhandler_tag = EVENTHANDLER_REGISTER(shutdown_pre_sync,
+	    ald_shutdown, NULL, SHUTDOWN_PRI_FIRST);
 
 	ALD_LOCK();
 
@@ -228,6 +229,8 @@
 {
 	struct alq *alq;
 
+	EVENTHANDLER_DEREGISTER(shutdown_pre_sync, alq_eventhandler_tag);
+
 	ALD_LOCK();
 
 	/* Ensure no new queues can be created. */