diff --git a/ctree.c b/ctree.c
index 4f7e6d0e..0e2fe7f6 100644
--- a/ctree.c
+++ b/ctree.c
@@ -686,6 +686,9 @@ static int balance_level(struct btrfs_trans_handle *trans,
 		/* promote the child to a root */
 		child = read_node_slot(root, mid, 0);
 		BUG_ON(!child);
+		ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
+		BUG_ON(ret);
+
 		root->node = child;
 		path->nodes[level] = NULL;
 		clean_tree_block(trans, root, mid);