diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6f17345..3f9a17f 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -134,4 +134,5 @@
 				       u8 *uuid);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
+int btrfs_balance(struct btrfs_root *dev_root);
 #endif