diff --git a/tests/unit/test_config.py b/tests/unit/test_config.py
index a08369e9c..1ef38b4fb 100644
--- a/tests/unit/test_config.py
+++ b/tests/unit/test_config.py
@@ -1,5 +1,6 @@
 import os
 import sys
+from pathlib import Path
 from unittest import mock
 
 import pytest
@@ -20,13 +21,13 @@ def _assert_config_read(environment, mock_config):
                 del os.environ[env_name]
         os.environ[environment] = "/MOCK"
 
-        module_dir = os.path.dirname(sys.modules["praw"].__file__)
-        environ_path = os.path.join(
-            "/MOCK", ".config" if environment == "HOME" else "", "praw.ini"
+        module_dir = Path(sys.modules["praw"].__file__).parent
+        environ_path = (
+            Path("/MOCK") / (".config" if environment == "HOME" else "") / "praw.ini"
         )
         locations = [
-            os.path.join(module_dir, "praw.ini"),
-            environ_path,
+            str(module_dir / "praw.ini"),
+            str(environ_path),
             "praw.ini",
         ]
 
diff --git a/tests/unit/util/test_token_manager.py b/tests/unit/util/test_token_manager.py
index 2423ef205..35c5088a3 100644
--- a/tests/unit/util/test_token_manager.py
+++ b/tests/unit/util/test_token_manager.py
@@ -1,5 +1,6 @@
 """Test praw.util.refresh_token_manager."""
 import sys
+from pathlib import Path
 from tempfile import NamedTemporaryFile
 from unittest import mock
 
@@ -15,6 +16,18 @@
 from ..test_reddit import DummyTokenManager
 
 
+def mock_path(read_data=None):
+    if read_data is not None:
+        mock_open = mock.mock_open(read_data=read_data)
+    else:
+        mock_open = mock.mock_open()
+
+    def mocked_open(self, *args, **kwargs):
+        return mock_open(self, *args, **kwargs)
+
+    return mock.patch.object(Path, "open", mocked_open), mock_open
+
+
 class DummyAuthorizer:
     def __init__(self, refresh_token):
         self.refresh_token = refresh_token
@@ -45,9 +58,9 @@ class TestFileTokenManager(UnitTest):
     def test_post_refresh_token_callback__writes_to_file(self):
         authorizer = DummyAuthorizer("token_value")
         manager = FileTokenManager("mock/dummy_path")
-        mock_open = mock.mock_open()
+        mock_patch, mock_open = mock_path()
 
-        with mock.patch("io.open", mock_open):
+        with mock_patch:
             manager.post_refresh_callback(authorizer)
 
         assert authorizer.refresh_token == "token_value"
@@ -60,16 +73,15 @@ def test_post_refresh_token_callback__writes_to_file(self):
     def test_pre_refresh_token_callback__reads_from_file(self):
         authorizer = DummyAuthorizer(None)
         manager = FileTokenManager("mock/dummy_path")
-        mock_open = mock.mock_open(read_data="token_value")
+        mock_patch, mock_open = mock_path(read_data="token_value")
 
-        with mock.patch("io.open", mock_open):
+        with mock_patch:
             manager.pre_refresh_callback(authorizer)
 
         assert authorizer.refresh_token == "token_value"
         call = mock_open.mock_calls[0]
-        path, mode, *_ = call.args
+        path, *_ = call.args
         assert path.match("mock/dummy_path")
-        assert mode == "r"
 
 
 class TestSQLiteTokenManager(UnitTest):
diff --git a/tox.ini b/tox.ini
index d16a253bb..f5978b1fb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,17 +1,12 @@
 [tox]
-envlist = py35,py36,py37,py38
-skip_missing_interpreters = true
+envlist = py37,py38,py39,py310,py311
 skipsdist = true
 
 [testenv]
 deps =
-    betamax >=0.8, <0.9
-    betamax-matchers >=0.3.0, <0.5
-    pytest >=2.7.3
-    flake8
+    .[test]
 commands =
     pytest
-    flake8 --exclude=.eggs,build,docs
 passenv =
     prawtest_client_id
     prawtest_client_secret