diff --git a/src/darsia/measure/wasserstein.py b/src/darsia/measure/wasserstein.py
index 79bf6645..018f6eb5 100644
--- a/src/darsia/measure/wasserstein.py
+++ b/src/darsia/measure/wasserstein.py
@@ -7,7 +7,7 @@
 import warnings
 from abc import abstractmethod
 from pathlib import Path
-from typing import Literal, Optional, Union
+from typing import Optional, Union
 
 import numpy as np
 import pyamg