diff --git a/utils/normalization.py b/utils/normalization.py
index 6ba5d72..8f9d432 100644
--- a/utils/normalization.py
+++ b/utils/normalization.py
@@ -4,7 +4,7 @@
 
 import torch
 import numpy as np
-from typing import Union, Tuple
+from typing import Tuple
 
 
 class RunningMeanStd:
@@ -158,4 +158,4 @@ def normalize(self, observations: torch.Tensor) -> torch.Tensor:
     
     def denormalize(self, observations: torch.Tensor) -> torch.Tensor:
         """Denormalize observations"""
-        return self.obs_rms.denormalize(observations)
\ No newline at end of file
+        return self.obs_rms.denormalize(observations)