diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d247429..54a1ad5 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3071,7 +3071,7 @@
 		release_stripe(sh);
 	}
 	spin_lock_irq(&conf->device_lock);
-	conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1);
+	conf->expand_progress = (sector_nr + i) * new_data_disks;
 	spin_unlock_irq(&conf->device_lock);
 	/* Ok, those stripe are ready. We can start scheduling
 	 * reads on the source stripes.