diff --git a/colossalai/amp/naive_amp/_utils.py b/colossalai/amp/naive_amp/_utils.py
index ad2a2ceed..7633705e1 100644
--- a/colossalai/amp/naive_amp/_utils.py
+++ b/colossalai/amp/naive_amp/_utils.py
@@ -1,4 +1,5 @@
 from typing import List
+
 from torch import Tensor