diff --git a/sys/miscfs/specfs/spec_vnops.c b/sys/miscfs/specfs/spec_vnops.c
index 8f7cf00cf80e..885318bad76f 100644
--- a/sys/miscfs/specfs/spec_vnops.c
+++ b/sys/miscfs/specfs/spec_vnops.c
@@ -397,7 +397,7 @@ spec_node_init(vnode_t *vp, dev_t rdev)
 		sd->sd_bdevvp = NULL;
 		sd->sd_iocnt = 0;
 		sd->sd_opened = false;
-		sd->sd_closing = false;
+		sd->sd_closing = NULL;
 		sn->sn_dev = sd;
 		sd = NULL;
 	} else {
@@ -1672,8 +1672,10 @@ spec_close(void *v)
 		sd->sd_bdevvp = NULL;
 	}
 	if (count == 0) {
+		KASSERTMSG(sd->sd_closing == NULL, "sd_closing=%p",
+		    sd->sd_closing);
 		sd->sd_opened = false;
-		sd->sd_closing = true;
+		sd->sd_closing = curlwp;
 	}
 	mutex_exit(&device_lock);
 
@@ -1722,8 +1724,9 @@ spec_close(void *v)
 	 * reacquiring the lock would deadlock.
 	 */
 	mutex_enter(&device_lock);
-	KASSERT(sd->sd_closing);
-	sd->sd_closing = false;
+	KASSERT(!sd->sd_opened);
+	KASSERTMSG(sd->sd_closing == curlwp, "sd_closing=%p", sd->sd_closing);
+	sd->sd_closing = NULL;
 	cv_broadcast(&specfs_iocv);
 	mutex_exit(&device_lock);
 
diff --git a/sys/miscfs/specfs/specdev.h b/sys/miscfs/specfs/specdev.h
index c55ab7aaa90a..4f3d315b5053 100644
--- a/sys/miscfs/specfs/specdev.h
+++ b/sys/miscfs/specfs/specdev.h
@@ -80,7 +80,7 @@ typedef struct specdev {
 	dev_t		sd_rdev;
 	volatile u_int	sd_iocnt;	/* # bdev/cdev_* operations active */
 	bool		sd_opened;	/* true if successfully opened */
-	bool		sd_closing;	/* true when bdev/cdev_close ongoing */
+	struct lwp	*sd_closing;	/* true when bdev/cdev_close ongoing */
 } specdev_t;
 
 /*