diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0e658c1d8211bd9644c354f1d699ac0a2e0bd757..c11b6fd408a68fc22c9fd5aeb41421d50c7e1252 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -724,7 +724,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
 		*num_bytes = calc_size;
 	else if (type & BTRFS_BLOCK_GROUP_RAID10)
-		*num_bytes = calc_size * num_stripes / sub_stripes;
+		*num_bytes = calc_size * (num_stripes / sub_stripes);
 	else
 		*num_bytes = calc_size * num_stripes;