diff --git a/freqtrade/freqai/RL/BaseEnvironment.py b/freqtrade/freqai/RL/BaseEnvironment.py
index d1a399c48..91c7501c6 100644
--- a/freqtrade/freqai/RL/BaseEnvironment.py
+++ b/freqtrade/freqai/RL/BaseEnvironment.py
@@ -2,7 +2,7 @@ import logging
 import random
 from abc import abstractmethod
 from enum import Enum
-from typing import Optional, Type, Union
+from typing import List, Optional, Type, Union
 
 import gymnasium as gym
 import numpy as np
@@ -141,7 +141,7 @@ class BaseEnvironment(gym.Env):
         Unique to the environment action count. Must be inherited.
         """
 
-    def action_masks(self) -> list[bool]:
+    def action_masks(self) -> List[bool]:
         return [self._is_valid(action.value) for action in self.actions]
 
     def seed(self, seed: int = 1):