1 files changed, 1 insertions, 1 deletions
diff --git a/volumes.h b/volumes.h
index f7761311..4ecb9931 100644
--- a/volumes.h
+++ b/volumes.h
@@ -156,7 +156,7 @@ struct map_lookup {
 static inline int check_crossing_stripes(u64 start, u64 len)
 {
 	return (start / BTRFS_STRIPE_LEN) !=
-	       ((start + len) / BTRFS_STRIPE_LEN);
+	       ((start + len - 1) / BTRFS_STRIPE_LEN);
 }
 
 int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,