diff --git a/src/PIL/_util.py b/src/PIL/_util.py
index b649500abb5..f7a69fae15d 100644
--- a/src/PIL/_util.py
+++ b/src/PIL/_util.py
@@ -11,7 +11,7 @@ def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
     return isinstance(f, (bytes, str, os.PathLike))
 
 
-def is_directory(f: Any) -> TypeGuard[bytes | str | Path]:
+def is_directory(f: Any) -> TypeGuard[StrOrBytesPath]:
     """Checks if an object is a string, and that it points to a directory."""
     return is_path(f) and os.path.isdir(f)