diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 4698d5f79575..43f231a467d5 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1653,6 +1653,7 @@ static int run (mddev_t *mddev)
 
 	/* device size must be a multiple of chunk size */
 	mddev->size &= ~(mddev->chunk_size/1024 -1);
+	mddev->resync_max_sectors = mddev->size << 1;
 
 	if (!conf->chunk_size || conf->chunk_size % 4) {
 		printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c
index f5ee16805111..495dee1d1e83 100644
--- a/drivers/md/raid6main.c
+++ b/drivers/md/raid6main.c
@@ -1813,6 +1813,7 @@ static int run (mddev_t *mddev)
 
 	/* device size must be a multiple of chunk size */
 	mddev->size &= ~(mddev->chunk_size/1024 -1);
+	mddev->resync_max_sectors = mddev->size << 1;
 
 	if (conf->raid_disks < 4) {
 		printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",