diff --git a/stable_baselines3/common/type_aliases.py b/stable_baselines3/common/type_aliases.py
index 139cd60..5ef94f9 100644
--- a/stable_baselines3/common/type_aliases.py
+++ b/stable_baselines3/common/type_aliases.py
@@ -1,6 +1,5 @@
-"""
-Common aliases for type hint
-"""
+"""Common aliases for type hints"""
+
 from typing import Union, Dict, Any, NamedTuple, List, Callable, Tuple
 
 import numpy as np