diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7862231a0750..d2aff7209070 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4357,7 +4357,7 @@ static int do_md_run(mddev_t * mddev)
 	mddev->barriers_work = 1;
 	mddev->ok_start_degraded = start_dirty_degraded;
 
-	if (start_readonly)
+	if (start_readonly && mddev->ro == 0)
 		mddev->ro = 2; /* read-only, but switch on first write */
 
 	err = mddev->pers->run(mddev);