diff --git a/pyleco_extras/gui/data_logger/data/plot_widget.py b/pyleco_extras/gui/data_logger/data/plot_widget.py
index 0ba33c2..6c7ec79 100644
--- a/pyleco_extras/gui/data_logger/data/plot_widget.py
+++ b/pyleco_extras/gui/data_logger/data/plot_widget.py
@@ -6,7 +6,7 @@
 
 import logging
 import math
-from typing import Any, Iterable, Protocol, Optional
+from typing import Any, Iterable, Protocol, Optional, Union
 
 import numpy as np
 import pint
@@ -29,7 +29,7 @@ def get_xy_data(
         x_key: Optional[str] = None,
         start: Optional[int] = None,
         stop: Optional[int] = None,
-    ) -> tuple[list[float]] | tuple[list[float], list[float]]: ...
+    ) -> Union[tuple[list[float]], tuple[list[float], list[float]]]: ...
 
     def get_data_keys(self) -> Iterable[str]: ...