diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 9fa479493642..783763f6845f 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3141,6 +3141,7 @@ static int raid1_run(struct mddev *mddev)
 	 * RAID1 needs at least one disk in active
 	 */
 	if (conf->raid_disks - mddev->degraded < 1) {
+		md_unregister_thread(&conf->thread);
 		ret = -EINVAL;
 		goto abort;
 	}