diff --git a/bdfr/archive_entry/base_archive_entry.py b/bdfr/archive_entry/base_archive_entry.py
index a33381e..57e36f8 100644
--- a/bdfr/archive_entry/base_archive_entry.py
+++ b/bdfr/archive_entry/base_archive_entry.py
@@ -2,12 +2,13 @@
 # coding=utf-8
 
 from abc import ABC, abstractmethod
+from typing import Union
 
 from praw.models import Comment, Submission
 
 
 class BaseArchiveEntry(ABC):
-    def __init__(self, source: (Comment, Submission)):
+    def __init__(self, source: Union[Comment, Submission]):
         self.source = source
         self.post_details: dict = {}
 
diff --git a/bdfr/archiver.py b/bdfr/archiver.py
index 4bd24f5..809af96 100644
--- a/bdfr/archiver.py
+++ b/bdfr/archiver.py
@@ -4,7 +4,7 @@
 import json
 import logging
 import re
-from typing import Iterator
+from typing import Iterator, Union
 
 import dict2xml
 import praw.models
@@ -65,7 +65,7 @@ class Archiver(RedditConnector):
         return results
 
     @staticmethod
-    def _pull_lever_entry_factory(praw_item: (praw.models.Submission, praw.models.Comment)) -> BaseArchiveEntry:
+    def _pull_lever_entry_factory(praw_item: Union[praw.models.Submission, praw.models.Comment]) -> BaseArchiveEntry:
         if isinstance(praw_item, praw.models.Submission):
             return SubmissionArchiveEntry(praw_item)
         elif isinstance(praw_item, praw.models.Comment):
@@ -73,7 +73,7 @@ class Archiver(RedditConnector):
         else:
             raise ArchiverError(f'Factory failed to classify item of type {type(praw_item).__name__}')
 
-    def write_entry(self, praw_item: (praw.models.Submission, praw.models.Comment)):
+    def write_entry(self, praw_item: Union[praw.models.Submission, praw.models.Comment]):
         if self.args.comment_context and isinstance(praw_item, praw.models.Comment):
             logger.debug(f'Converting comment {praw_item.id} to submission {praw_item.submission.id}')
             praw_item = praw_item.submission
diff --git a/bdfr/file_name_formatter.py b/bdfr/file_name_formatter.py
index 70bd527..4a039c9 100644
--- a/bdfr/file_name_formatter.py
+++ b/bdfr/file_name_formatter.py
@@ -6,7 +6,7 @@ import platform
 import re
 import subprocess
 from pathlib import Path
-from typing import Optional
+from typing import Optional, Union
 
 from praw.models import Comment, Submission
 
@@ -34,7 +34,7 @@ class FileNameFormatter:
         self.directory_format_string: list[str] = directory_format_string.split('/')
         self.time_format_string = time_format_string
 
-    def _format_name(self, submission: (Comment, Submission), format_string: str) -> str:
+    def _format_name(self, submission: Union[Comment, Submission], format_string: str) -> str:
         if isinstance(submission, Submission):
             attributes = self._generate_name_dict_from_submission(submission)
         elif isinstance(submission, Comment):
diff --git a/tests/test_file_name_formatter.py b/tests/test_file_name_formatter.py
index e7f1ebe..0492536 100644
--- a/tests/test_file_name_formatter.py
+++ b/tests/test_file_name_formatter.py
@@ -6,7 +6,7 @@ import sys
 import unittest.mock
 from datetime import datetime
 from pathlib import Path
-from typing import Optional
+from typing import Optional, Type, Union
 from unittest.mock import MagicMock
 
 import praw.models
@@ -33,7 +33,7 @@ def submission() -> MagicMock:
     return test
 
 
-def do_test_string_equality(result: [Path, str], expected: str) -> bool:
+def do_test_string_equality(result: Union[Path, str], expected: str) -> bool:
     if platform.system() == 'Windows':
         expected = FileNameFormatter._format_for_windows(expected)
     return str(result).endswith(expected)
@@ -411,7 +411,7 @@ def test_windows_max_path(tmp_path: Path):
 ))
 def test_name_submission(
         test_reddit_id: str,
-        test_downloader: type(BaseDownloader),
+        test_downloader: Type[BaseDownloader],
         expected_names: set[str],
         reddit_instance: praw.reddit.Reddit,
 ):