diff --git a/beets/util/hidden.py b/beets/util/hidden.py
index dc0f3813c..415506be5 100644
--- a/beets/util/hidden.py
+++ b/beets/util/hidden.py
@@ -20,9 +20,10 @@ import os
 import stat
 import sys
 from pathlib import Path
+from typing import Union
 
 
-def is_hidden(path: bytes | Path) -> bool:
+def is_hidden(path: Union[bytes, Path]) -> bool:
     """
     Determine whether the given path is treated as a 'hidden file' by the OS.
     """