diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d8a738a1..69e9d743 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,9 +2,6 @@ name: Test
 
 on:
   pull_request:
-    branches:
-      - master
-      - maintenance/**
   push:
     branches:
       - master
@@ -17,118 +14,42 @@ env:
 
 jobs:
   test:
-    runs-on: ${{ matrix.os }}
     strategy:
-      fail-fast: false
       matrix:
-        include:
-          - os: ubuntu-18.04
-            python: "2.7"
-            toxenv: cp27
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.4"
-            toxenv: cp34
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.5"
-            toxenv: cp35
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.6"
-            toxenv: cp36
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.7"
-            toxenv: cp37
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.8"
-            toxenv: cp38
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "3.9"
-            toxenv: cp39
-            continue-on-error: false
-
-          - os: ubuntu-18.04
-            python: "pypy2"
-            toxenv: pp2
-            continue-on-error: false
-          - os: ubuntu-18.04
-            python: "pypy3"
-            toxenv: pp3
-            continue-on-error: false
-
-          - os: ubuntu-20.04
-            python: "2.7"
-            toxenv: cp27
-            continue-on-error: false
-          - os: ubuntu-20.04
-            python: "3.5"
-            toxenv: cp35
-            continue-on-error: false
-          - os: ubuntu-20.04
-            python: "pypy2"
-            toxenv: pp2
-            continue-on-error: false
-          - os: ubuntu-20.04
-            python: "pypy3"
-            toxenv: pp3
-            continue-on-error: false
-
-          - os: macos-10.15
-            python: "3.5"
-            toxenv: cp35
-            continue-on-error: true
-          - os: macos-11.0
-            python: "3.5"
-            toxenv: cp35
-            continue-on-error: true
-          - os: windows-2019
-            python: "3.5"
-            toxenv: cp35
-            continue-on-error: false
-
-          # 3.10 Alpha
-          - os: ubuntu-18.04
-            python: "3.10.0-alpha.2"
-            toxenv: "cp310"
-            continue-on-error: false
-          - os: macos-11.0
-            python: "3.10.0-alpha.2"
-            toxenv: "cp310"
-            continue-on-error: true
-          - os: windows-2019
-            python: "3.10.0-alpha.2"
-            toxenv: "cp310"
-            continue-on-error: true
-
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "pypy3.9", "pypy3.10"]
+        os: [windows-latest, ubuntu-latest, macos-latest]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}  
     steps:
-      - uses: actions/checkout@v2
-      - name: Setup python
-        uses: actions/setup-python@v2
-        with:
-          python-version: ${{ matrix.python }}
-      - name: Install
-        run: pip install -q -r "tox-requirements.txt"
-      - name: Run tests
-        continue-on-error: ${{ matrix.continue-on-error }}
-        env:
-          TOXENV: ${{ matrix.toxenv }}
-        run: tox -v
+    - uses: actions/checkout@v4
+    - name: Setup python
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install
+      run: |
+        pip install -e .
+        pip install -r "test_requirements.txt"
+        pip --version
+    - name: Run tests with unittest
+      run: |
+        coverage run --branch -m unittest discover -v -t . haas
+    - name: Run tests with haas
+      run: |
+        python -m haas haas
+    - name: Print coverage report
+      run: |
+        coverage report
 
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - name: Setup python
-        uses: actions/setup-python@v2
-        with:
-          python-version: "3.7"
-      - name: Install
-        run: pip install -q -r "tox-requirements.txt"
-      - name: Run tests
-        env:
-          TOXENV: flake8
-        run: tox -v
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v4
+      with:
+        python-version: 3.8
+    - name: Install flake8
+      run: python -m pip install flake8
+    - name: Lint codebase
+      run: python -m flake8 haas
diff --git a/haas/plugins/discoverer.py b/haas/plugins/discoverer.py
index 74a5ca09..ca2f3de5 100644
--- a/haas/plugins/discoverer.py
+++ b/haas/plugins/discoverer.py
@@ -7,6 +7,9 @@
 from __future__ import absolute_import, unicode_literals
 
 from fnmatch import fnmatch
+from importlib import import_module
+from os import getcwd
+from pathlib import Path
 import logging
 import os
 import sys
@@ -16,7 +19,6 @@
 from haas.module_import_error import ModuleImportError
 from haas.suite import find_test_cases
 from haas.testing import unittest
-from haas.utils import get_module_by_name
 from .i_discoverer_plugin import IDiscovererPlugin
 
 logger = logging.getLogger(__name__)
@@ -41,9 +43,11 @@ def test_error(self):
 
 
 def get_relpath(top_level_directory, fullpath):
-    normalized = os.path.normpath(fullpath)
-    relpath = os.path.relpath(normalized, top_level_directory)
-    if os.path.isabs(relpath) or relpath.startswith('..'):
+    top_level = Path(top_level_directory).resolve()
+    normalized = Path(fullpath).resolve()
+    try:
+        relpath = str(normalized.relative_to(top_level))
+    except ValueError:
         raise ValueError('Path not within project: {0}'.format(fullpath))
     return relpath
 
@@ -77,7 +81,7 @@ def find_module_by_name(full_name):
     module_attributes = []
     while True:
         try:
-            module = get_module_by_name(module_name)
+            module = import_module(module_name)
         except ImportError:
             if '.' in module_name:
                 module_name, attribute = module_name.rsplit('.', 1)
@@ -365,7 +369,7 @@ def _load_from_file(self, filepath, top_level_directory):
         module_name = get_module_name(top_level_directory, filepath)
         logger.debug('Loading tests from %r', module_name)
         try:
-            module = get_module_by_name(module_name)
+            module = import_module(module_name)
         except Exception:
             test = _create_import_error_test(module_name)
         else:
@@ -421,7 +425,7 @@ def discover_filtered_tests(self, filter_name, top_level_directory=None,
         """
         if top_level_directory is None:
             top_level_directory = find_top_level_directory(
-                os.getcwd())
+                getcwd())
 
         logger.debug('Discovering filtered tests: filter_name=%r, '
                      'top_level_directory=%r, pattern=%r', top_level_directory,
diff --git a/haas/plugins/i_discoverer_plugin.py b/haas/plugins/i_discoverer_plugin.py
index 7a17ce3c..dc2e0bee 100644
--- a/haas/plugins/i_discoverer_plugin.py
+++ b/haas/plugins/i_discoverer_plugin.py
@@ -8,13 +8,10 @@
 
 from abc import ABCMeta, abstractmethod
 
-from six import add_metaclass
-
 from haas.utils import abstractclassmethod
 
 
-@add_metaclass(ABCMeta)
-class IDiscovererPlugin(object):
+class IDiscovererPlugin(object, metaclass=ABCMeta):
 
     @abstractclassmethod
     def from_args(cls, args, arg_prefix, loader):
diff --git a/haas/plugins/i_hook_plugin.py b/haas/plugins/i_hook_plugin.py
index e3826f63..fa16238b 100644
--- a/haas/plugins/i_hook_plugin.py
+++ b/haas/plugins/i_hook_plugin.py
@@ -8,13 +8,10 @@
 
 import abc
 
-from six import add_metaclass
-
 from haas.utils import abstractclassmethod
 
 
-@add_metaclass(abc.ABCMeta)
-class IHookPlugin(object):
+class IHookPlugin(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def setup(self):  # pragma: no cover
diff --git a/haas/plugins/i_result_handler_plugin.py b/haas/plugins/i_result_handler_plugin.py
index 6a20913d..80c15512 100644
--- a/haas/plugins/i_result_handler_plugin.py
+++ b/haas/plugins/i_result_handler_plugin.py
@@ -8,13 +8,10 @@
 
 from abc import ABCMeta, abstractmethod
 
-from six import add_metaclass
-
 from haas.utils import abstractclassmethod
 
 
-@add_metaclass(ABCMeta)
-class IResultHandlerPlugin(object):
+class IResultHandlerPlugin(object, metaclass=ABCMeta):
 
     @abstractclassmethod
     def from_args(cls, args, name, dest_prefix, test_count):
diff --git a/haas/plugins/i_runner_plugin.py b/haas/plugins/i_runner_plugin.py
index 25d134c3..65e3de81 100644
--- a/haas/plugins/i_runner_plugin.py
+++ b/haas/plugins/i_runner_plugin.py
@@ -8,13 +8,10 @@
 
 import abc
 
-from six import add_metaclass
-
 from haas.utils import abstractclassmethod
 
 
-@add_metaclass(abc.ABCMeta)
-class IRunnerPlugin(object):
+class IRunnerPlugin(object, metaclass=abc.ABCMeta):
 
     @abstractclassmethod
     def from_args(cls, args, arg_prefix):
diff --git a/haas/plugins/parallel_runner.py b/haas/plugins/parallel_runner.py
index 803e0cb4..d1d13b93 100644
--- a/haas/plugins/parallel_runner.py
+++ b/haas/plugins/parallel_runner.py
@@ -1,10 +1,10 @@
+from importlib import import_module
 from multiprocessing import Pool
 import time
 
 from haas.module_import_error import ModuleImportError
 from haas.suite import find_test_cases
 from haas.result import ResultCollector
-from haas.utils import get_module_by_name
 from .i_result_handler_plugin import IResultHandlerPlugin
 from .runner import BaseTestRunner
 
@@ -82,7 +82,7 @@ def from_args(cls, args, arg_prefix):
             initializer = None
         else:
             module_name, initializer_name = initializer_spec.rsplit('.', 1)
-            init_module = get_module_by_name(module_name)
+            init_module = import_module(module_name)
             initializer = getattr(init_module, initializer_name)
         return cls(process_count=args.processes, initializer=initializer,
                    maxtasksperchild=args.process_max_tasks)
diff --git a/haas/plugins/tests/test_discoverer.py b/haas/plugins/tests/test_discoverer.py
index 0314f8a5..929ed5d1 100644
--- a/haas/plugins/tests/test_discoverer.py
+++ b/haas/plugins/tests/test_discoverer.py
@@ -20,6 +20,7 @@
 from haas.module_import_error import ModuleImportError
 from haas.suite import find_test_cases, TestSuite
 from haas.utils import cd
+from haas.plugins import discoverer
 from ..discoverer import (
     Discoverer,
     filter_test_suite,
@@ -451,7 +452,7 @@ def test_discover_class(self):
     def test_discover_no_top_level(self):
         getcwd = mock.Mock()
         getcwd.return_value = self.tmpdir
-        with mock.patch.object(os, 'getcwd', getcwd):
+        with mock.patch.object(discoverer, 'getcwd', getcwd):
             suite = self.discoverer.discover(
                 'TestCase',
             )
diff --git a/haas/plugins/tests/test_result_handlers.py b/haas/plugins/tests/test_result_handlers.py
index b1c98af1..ff2aeb1b 100644
--- a/haas/plugins/tests/test_result_handlers.py
+++ b/haas/plugins/tests/test_result_handlers.py
@@ -1,7 +1,7 @@
 from datetime import datetime, timedelta
 import statistics
 
-from six.moves import StringIO
+from io import StringIO
 
 from haas.result import TestResult, TestCompletionStatus, TestDuration
 from haas.testing import unittest
@@ -53,7 +53,7 @@ def test_output_stop_test_run_success(self, stderr):
         output = stderr.getvalue()
         output_start = '\n\nTest timing report\n' + handler.separator2
         self.assertTrue(output.startswith(output_start))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?00:10\.123 test_method \(')
 
     @mock.patch('time.ctime')
@@ -234,7 +234,7 @@ def test_output_with_error_on_stop_test_run(self, stderr):
         output = stderr.getvalue()
         output_start = '\n\nTest timing report\n' + handler.separator2
         self.assertTrue(output.startswith(output_start))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?1543:00:12\.234 test_method \(')
 
     @mock.patch('sys.stderr', new_callable=StringIO)
@@ -261,7 +261,7 @@ def test_output_with_failure_on_stop_test_run(self, stderr):
         output = stderr.getvalue()
         output_start = '\n\nTest timing report\n' + handler.separator2
         self.assertTrue(output.startswith(output_start))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?1:01:14\.567 test_method \(')
 
     def _calculate_statistics(self, test_durations):
@@ -341,7 +341,7 @@ class Case(_test_cases.TestCase):
         output = stderr.getvalue()
         output_start = '\n\nTest timing report\n' + handler.separator2
         self.assertTrue(output.startswith(output_start))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?00:09\.123 test_method \(')
         self.assertIn(expected_stats, output)
 
diff --git a/haas/result.py b/haas/result.py
index de1a3e10..1a3a834f 100644
--- a/haas/result.py
+++ b/haas/result.py
@@ -14,8 +14,7 @@
 import traceback
 import warnings
 
-import six
-from six.moves import StringIO
+from io import StringIO
 
 from .error_holder import ErrorHolder
 
@@ -65,7 +64,7 @@ def _count_relevant_tb_levels(tb):
 
 
 def _decode(line, encoding):
-    if isinstance(line, six.text_type):
+    if isinstance(line, str):
         return line
     try:
         return line.decode(encoding)
diff --git a/haas/tests/builder.py b/haas/tests/builder.py
index a2c3f9bf..cd44b784 100644
--- a/haas/tests/builder.py
+++ b/haas/tests/builder.py
@@ -10,13 +10,10 @@
 import os
 import textwrap
 
-from six import add_metaclass
-
 from ..testing import unittest
 
 
-@add_metaclass(abc.ABCMeta)
-class Importable(object):
+class Importable(object, metaclass=abc.ABCMeta):
 
     def __init__(self, name, contents=()):
         self.name = name
diff --git a/haas/tests/test_buffering.py b/haas/tests/test_buffering.py
index f279a349..79f4edde 100644
--- a/haas/tests/test_buffering.py
+++ b/haas/tests/test_buffering.py
@@ -9,7 +9,7 @@
 from datetime import datetime, timedelta
 import sys
 
-from six.moves import StringIO
+from io import StringIO
 
 from haas.tests.compat import mock
 from ..plugins.i_result_handler_plugin import IResultHandlerPlugin
diff --git a/haas/tests/test_loader.py b/haas/tests/test_loader.py
index afe0bf55..a64fbba4 100644
--- a/haas/tests/test_loader.py
+++ b/haas/tests/test_loader.py
@@ -8,8 +8,6 @@
 
 import unittest as python_unittest
 
-import six
-
 from haas.testing import unittest
 
 from . import _test_cases
@@ -111,8 +109,7 @@ def assertSuiteClasses(self, suite, klass):
 
     def test_find_all_cases_in_module(self):
         cases = self.loader.get_test_cases_from_module(_test_cases)
-        six.assertCountEqual(
-            self,
+        self.assertCountEqual(
             cases, [_test_cases.TestCase, _test_cases.PythonTestCase])
 
     def test_load_all_cases_in_module(self):
diff --git a/haas/tests/test_parallel_runner.py b/haas/tests/test_parallel_runner.py
index 6590fd38..d190b6ca 100644
--- a/haas/tests/test_parallel_runner.py
+++ b/haas/tests/test_parallel_runner.py
@@ -2,7 +2,7 @@
 from datetime import datetime, timedelta
 import time
 
-from six.moves import StringIO
+from io import StringIO
 
 from ..plugins.discoverer import _create_import_error_test
 from ..plugins.parallel_runner import ChildResultHandler, ParallelTestRunner
diff --git a/haas/tests/test_quiet_result_handler.py b/haas/tests/test_quiet_result_handler.py
index 556197ef..3bd4f103 100644
--- a/haas/tests/test_quiet_result_handler.py
+++ b/haas/tests/test_quiet_result_handler.py
@@ -8,7 +8,7 @@
 
 from datetime import datetime, timedelta
 
-from six.moves import StringIO
+from io import StringIO
 
 from ..plugins.result_handler import QuietTestResultHandler
 from ..result import (
@@ -46,7 +46,7 @@ def test_output_stop_test_run(self, stderr):
         output = stderr.getvalue()
         self.assertTrue(output.startswith('\n' + handler.separator2))
         self.assertTrue(output.endswith('OK\n'))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?Ran 0 tests.*?OK')
 
     @mock.patch('sys.stderr', new_callable=StringIO)
@@ -226,7 +226,7 @@ def test_no_output_with_error_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case,).replace('(', r'\(').replace(')', r'\)')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?RuntimeError'.format(
                 description))
 
@@ -254,7 +254,7 @@ def test_no_output_with_failure_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case,).replace('(', r'\(').replace(')', r'\)').replace('\n', '')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?AssertionError'.format(
                 description))
         # The contents of unittest.TestCase should not be in the traceback
diff --git a/haas/tests/test_standard_result_handler.py b/haas/tests/test_standard_result_handler.py
index 84e1658c..69f6a255 100644
--- a/haas/tests/test_standard_result_handler.py
+++ b/haas/tests/test_standard_result_handler.py
@@ -8,7 +8,7 @@
 
 from datetime import datetime, timedelta
 
-from six.moves import StringIO
+from io import StringIO
 
 from ..plugins.result_handler import StandardTestResultHandler
 from ..result import (
@@ -46,7 +46,7 @@ def test_output_stop_test_run(self, stderr):
         output = stderr.getvalue()
         self.assertTrue(output.startswith('\n' + handler.separator2))
         self.assertTrue(output.endswith('OK\n'))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?Ran 0 tests.*?OK')
 
     @mock.patch('sys.stderr', new_callable=StringIO)
@@ -226,7 +226,7 @@ def test_no_output_with_error_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case).replace('(', r'\(').replace(')', r'\)')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?RuntimeError'.format(
                 description))
 
@@ -254,7 +254,7 @@ def test_no_output_with_failure_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case).replace('(', r'\(').replace(')', r'\)').replace('\n', '')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?AssertionError'.format(
                 description))
         # The contents of unittest.TestCase should not be in the traceback
diff --git a/haas/tests/test_test_duration_ordering.py b/haas/tests/test_test_duration_ordering.py
index 7f0059ec..83a97698 100644
--- a/haas/tests/test_test_duration_ordering.py
+++ b/haas/tests/test_test_duration_ordering.py
@@ -9,8 +9,6 @@
 from datetime import datetime, timedelta
 import sys
 
-import six
-
 from ..result import TestDuration
 from ..testing import unittest
 
@@ -76,11 +74,11 @@ def test_equality(self):
         self.assertEqual(duration1, duration2)
         self.assertLessEqual(duration1, duration2)
         self.assertGreaterEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not less than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not less than'):
             self.assertLess(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not greater than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not greater than'):
             self.assertGreater(duration1, duration2)
 
         self.assertNotEqual(duration1, object())
@@ -99,11 +97,11 @@ def test_equality(self):
         self.assertEqual(duration1, duration2)
         self.assertLessEqual(duration1, duration2)
         self.assertGreaterEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not less than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not less than'):
             self.assertLess(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not greater than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not greater than'):
             self.assertGreater(duration1, duration2)
 
     def test_lessthan(self):
@@ -122,11 +120,11 @@ def test_lessthan(self):
         self.assertNotEqual(duration1, duration2)
         self.assertLess(duration1, duration2)
         self.assertLessEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not greater than or equal to'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not greater than or equal to'):
             self.assertGreaterEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not greater than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not greater than'):
             self.assertGreater(duration1, duration2)
 
     def test_greaterthan(self):
@@ -145,9 +143,9 @@ def test_greaterthan(self):
         self.assertNotEqual(duration1, duration2)
         self.assertGreater(duration1, duration2)
         self.assertGreaterEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not less than or equal to'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not less than or equal to'):
             self.assertLessEqual(duration1, duration2)
-        with six.assertRaisesRegex(
-                self, self.failureException, 'not less than'):
+        with self.assertRaisesRegex(
+                self.failureException, 'not less than'):
             self.assertLess(duration1, duration2)
diff --git a/haas/tests/test_verbose_result_handler.py b/haas/tests/test_verbose_result_handler.py
index b136a1e5..a10b3491 100644
--- a/haas/tests/test_verbose_result_handler.py
+++ b/haas/tests/test_verbose_result_handler.py
@@ -9,7 +9,7 @@
 from datetime import datetime, timedelta
 from time import ctime
 
-from six.moves import StringIO
+from io import StringIO
 
 from ..plugins.result_handler import VerboseTestResultHandler
 from ..result import (
@@ -47,7 +47,7 @@ def test_no_output_stop_test_run(self, stderr):
         output = stderr.getvalue()
         self.assertTrue(output.startswith('\n' + handler.separator2))
         self.assertTrue(output.endswith('OK\n'))
-        self.assertRegexpMatches(
+        self.assertRegex(
             output.replace('\n', ''), r'--+.*?Ran 0 tests.*?OK')
 
     @mock.patch('time.ctime')
@@ -232,7 +232,7 @@ def test_output_with_error_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case).replace('(', r'\(').replace(')', r'\)')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?RuntimeError'.format(
                 description))
 
@@ -260,7 +260,7 @@ def test_output_with_failure_on_stop_test_run(self, stderr):
         output = stderr.getvalue().replace('\n', '')
         description = handler.get_test_description(
             case).replace('(', r'\(').replace(')', r'\)').replace('\n', '')
-        self.assertRegexpMatches(
+        self.assertRegex(
             output, '{0}.*?Traceback.*?AssertionError'.format(
                 description))
         # The contents of unittest.TestCase should not be in the traceback
diff --git a/haas/utils.py b/haas/utils.py
index 93a5057b..677922f7 100644
--- a/haas/utils.py
+++ b/haas/utils.py
@@ -8,10 +8,8 @@
 
 import logging
 import os
-import sys
 import re
-
-import six
+import sys
 
 import haas
 
@@ -40,18 +38,6 @@ def configure_logging(level):
                 logging.getLevelName(actual_level))
 
 
-if six.PY2:
-    def get_module_by_name(name):
-        """Import a module and return the imported module object.
-
-        """
-        __import__(name)
-        return sys.modules[name]
-else:
-    import importlib
-    get_module_by_name = importlib.import_module
-
-
 UNCAMELCASE_FIRST_PASS = re.compile(
     r'(?P<before>.)(?P<caps>[A-Z]+)')
 UNCAMELCASE_SECOND_PASS = re.compile(
diff --git a/setup.py b/setup.py
index 3bcff0d7..f250d729 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,6 @@
 # This software may be modified and distributed under the terms
 # of the 3-clause BSD license.  See the LICENSE.txt file for details.
 import os
-import sys
 import subprocess
 
 from setuptools import setup
@@ -105,21 +104,11 @@ def write_version_py(filename='haas/_version.py'):
 
 
 if __name__ == "__main__":
-    install_requires = ['six']
-    common_requires = ['enum34', 'statistics']
-    py26_requires = [
-        'stevedore >= 1.0.0, < 1.10.0',
-        'unittest2',
-        'argparse',
-        'ordereddict'] + common_requires
-    py34_requires = ['stevedore >= 1.0.0, < 1.12.0']
-    py33_requires = py34_requires + common_requires
-    if sys.version_info < (2, 7):
-        install_requires += py26_requires
-    elif sys.version_info < (3, 4):
-        install_requires += py33_requires
-    else:
-        install_requires = py34_requires
+    install_requires = [
+        'enum34',
+        'statistics',
+        'stevedore >= 3.5.2, < 5.0.0',
+    ]
 
     write_version_py()
     from haas import __version__
@@ -143,13 +132,14 @@ def write_version_py(filename='haas/_version.py'):
             'Operating System :: POSIX',
             'Operating System :: Unix',
             'Programming Language :: Python',
-            'Programming Language :: Python :: 2',
-            'Programming Language :: Python :: 2.7',
             'Programming Language :: Python :: 3',
-            'Programming Language :: Python :: 3.4',
-            'Programming Language :: Python :: 3.5',
-            'Programming Language :: Python :: 3.6',
+            'Programming Language :: Python :: 3 :: Only',
             'Programming Language :: Python :: 3.7',
+            'Programming Language :: Python :: 3.8',
+            'Programming Language :: Python :: 3.9',
+            'Programming Language :: Python :: 3.10',
+            'Programming Language :: Python :: 3.11',
+            'Programming Language :: Python :: 3.12',
             'Topic :: Software Development',
             'Topic :: Software Development :: Testing',
         ],
@@ -179,13 +169,4 @@ def write_version_py(filename='haas/_version.py'):
                 'timing = haas.plugins.result_handler:TimingResultHandler',
             ]
         },
-        extras_require={
-            ':python_version=="2.6"': py26_requires,
-            ':python_version=="2.7"': py33_requires,
-            ':python_version=="3.3"': py33_requires,
-            ':python_version=="3.4"': py34_requires,
-            ':python_version=="3.5"': py34_requires,
-            ':python_version=="3.6"': py34_requires,
-            ':python_version=="3.7"': py34_requires,
-        },
     )
diff --git a/test_requirements.txt b/test_requirements.txt
index f345fa94..ff0b4f14 100644
--- a/test_requirements.txt
+++ b/test_requirements.txt
@@ -1,5 +1,4 @@
 coverage
 unittest2; python_version == '2.6'
 mock; python_version < '3.3'
-six
 testfixtures
diff --git a/tox.ini b/tox.ini
index 2cab8678..1d0c75dc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = cp{27,34,35,36,37,38,39,310},pp{2,3},flake8
+envlist = cp{27,34,35,36,37,38,39,310,311,312},pp{2,3},flake8
 minversion=2.7
 
 [testenv]
@@ -20,7 +20,9 @@ basepython =
     cp37: {env:TOXPY37:python3.7}
     cp38: {env:TOXPY38:python3.8}
     cp39: {env:TOXPY38:python3.9}
-    cp310: {env:TOXPY38:python3.10}
+    cp310: {env:TOXPY310:python3.10}
+    cp311: {env:TOXPY311:python3.12}
+    cp312: {env:TOXPY312:python3.12}
     pp2: {env:TOXPYPY:pypy}
     pp3: {env:TOXPYPY3:pypy3}