diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d24adc5..4006a9b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2988,6 +2988,7 @@ static int raid1_run(struct mddev *mddev)
 	mddev->thread = conf->thread;
 	conf->thread = NULL;
 	mddev->private = conf;
+	set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
 
 	md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));