diff --git a/.github/workflows/publish-pypi.yml b/.github/workflows/publish-pypi.yml
index 4020d8d..823105d 100644
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -7,12 +7,16 @@ jobs:
   build-n-publish:
     name: Build and publish Python 🐍 distributions 📦 to PyPI and TestPyPI
     runs-on: ubuntu-latest
+    environment: release
+    permissions:
+      # IMPORTANT: this permission is mandatory for trusted publishing
+      id-token: write
 
     steps:
     - uses: actions/checkout@v3
       with:
         ref: main
-    - name: Set up Python 3.8
+    - name: Set up Python 3.10
       uses: actions/setup-python@v4
       with:
         python-version: '3.10'
@@ -27,7 +31,4 @@ jobs:
         python setup.py sdist bdist_wheel
 
     - name: Publish distribution to PyPI
-      uses: pypa/gh-action-pypi-publish@master
-      with:
-        user: __token__
-        password: ${{ secrets.pypi_api_key }}
+      uses: pypa/gh-action-pypi-publish@release/v1
diff --git a/.github/workflows/run_tox.yml b/.github/workflows/run_tox.yml
index 7136e72..57edeb5 100644
--- a/.github/workflows/run_tox.yml
+++ b/.github/workflows/run_tox.yml
@@ -3,12 +3,22 @@ name: Tests
 on: [push, pull_request]
 
 jobs:
+  pre-commit:
+    name: pre-commit
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+      - uses: pre-commit/action@v3.0.0
+
   test:
     runs-on: ubuntu-latest
     strategy:
       max-parallel: 4
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
 
     steps:
     - uses: actions/checkout@v3
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1cb5edf..9a40a02 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,35 +1,27 @@
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v4.5.0
     hooks:
+      - id: check-ast
+      - id: check-builtin-literals
+      - id: check-docstring-first
+      - id: check-merge-conflict
+      - id: check-toml
       - id: check-yaml
+      - id: debug-statements
       - id: end-of-file-fixer
       - id: trailing-whitespace
 
-  - repo: https://github.com/pycqa/isort
-    rev: 5.12.0
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.1.11  # check that this version matches the requirements.txt
     hooks:
-      - id: isort
-        name: isort (python)
-
-
-  - repo: https://github.com/PyCQA/flake8
-    rev: '6.0.0'
-    hooks:
-    -   id: flake8
-        additional_dependencies:
-          - flake8-bugbear==23.1.20
-          - flake8-comprehensions==3.10.1
-          - flake8-pytest-style==1.6
-          - flake8-noqa==1.3
-          - pep8-naming==0.13.3
+      - id: ruff
 
   - repo: https://github.com/pre-commit/pygrep-hooks
     rev: v1.10.0
     hooks:
       - id: rst-backticks
 
-
   - repo: meta
     hooks:
       - id: check-hooks-apply
diff --git a/.readthedocs.yml b/.readthedocs.yml
index 409b84d..c55a20b 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -18,9 +18,9 @@ formats: all
 
 
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
   tools:
-    python: "3.9"
+    python: "3.10"
 
 python:
   install:
diff --git a/.ruff.toml b/.ruff.toml
new file mode 100644
index 0000000..d9d9603
--- /dev/null
+++ b/.ruff.toml
@@ -0,0 +1,85 @@
+
+line-length = 120
+indent-width = 4
+
+target-version = "py38"
+src = ["src", "test"]
+
+# https://docs.astral.sh/ruff/settings/#ignore-init-module-imports
+ignore-init-module-imports = true
+
+extend-exclude = ["__init__.py"]
+
+select = [
+    "E", "W",   # https://docs.astral.sh/ruff/rules/#pycodestyle-e-w
+    "I",        # https://docs.astral.sh/ruff/rules/#isort-i
+    "UP",       # https://docs.astral.sh/ruff/rules/#pyupgrade-up
+
+    "A",        # https://docs.astral.sh/ruff/rules/#flake8-builtins-a
+    "ASYNC",    # https://docs.astral.sh/ruff/rules/#flake8-async-async
+    "C4",       # https://docs.astral.sh/ruff/rules/#flake8-comprehensions-c4
+    "EM",       # https://docs.astral.sh/ruff/rules/#flake8-errmsg-em
+    "FIX",      # https://docs.astral.sh/ruff/rules/#flake8-fixme-fix
+    "INP",      # https://docs.astral.sh/ruff/rules/#flake8-no-pep420-inp
+    "ISC",      # https://docs.astral.sh/ruff/rules/#flake8-implicit-str-concat-isc
+    "PIE",      # https://docs.astral.sh/ruff/rules/#flake8-pie-pie
+    "PT",       # https://docs.astral.sh/ruff/rules/#flake8-pytest-style-pt
+    "PTH",      # https://docs.astral.sh/ruff/rules/#flake8-use-pathlib-pth
+    "RET",      # https://docs.astral.sh/ruff/rules/#flake8-return-ret
+    "SIM",      # https://docs.astral.sh/ruff/rules/#flake8-simplify-sim
+    "SLOT",     # https://docs.astral.sh/ruff/rules/#flake8-slots-slot
+    "T10",      # https://docs.astral.sh/ruff/rules/#flake8-debugger-t10
+    "TCH",      # https://docs.astral.sh/ruff/rules/#flake8-type-checking-tch
+    "TD",       # https://docs.astral.sh/ruff/rules/#flake8-todos-td
+
+    "TRY",      # https://docs.astral.sh/ruff/rules/#tryceratops-try
+    "FLY",      # https://docs.astral.sh/ruff/rules/#flynt-fly
+    "PERF",     # https://docs.astral.sh/ruff/rules/#perflint-perf
+    "RUF",      # https://docs.astral.sh/ruff/rules/#ruff-specific-rules-ruf
+
+    "PL",       # https://docs.astral.sh/ruff/rules/#pylint-pl
+]
+
+ignore = [
+    "RET501",   # https://docs.astral.sh/ruff/rules/unnecessary-return-none/#unnecessary-return-none-ret501
+    "TRY400",   # https://docs.astral.sh/ruff/rules/error-instead-of-exception/
+
+    "A003",     # https://docs.astral.sh/ruff/rules/builtin-attribute-shadowing/
+]
+
+
+[format]
+# Use single quotes for non-triple-quoted strings.
+quote-style = "single"
+
+
+
+[lint.per-file-ignores]
+"doc/*" = [
+    "A001",     # A001 Variable `copyright` is shadowing a Python builtin
+    "E402",     # E402 Module level import not at top of file
+    "INP001",   # INP001 File `FILE_NAME` is part of an implicit namespace package. Add an `__init__.py`.
+    "PTH100",   # PTH100 `os.path.abspath()` should be replaced by `Path.resolve()`
+    "PTH118",   # PTH118 `os.path.join()` should be replaced by `Path` with `/` operator
+]
+
+"tests/*" = [
+    "INP001",   # INP001 File `FILE_NAME` is part of an implicit namespace package. Add an `__init__.py`.
+    "ISC002",   # ISC002 Implicitly concatenated string literals over multiple lines
+]
+
+"setup.py" = ["PTH123"]
+
+"src/sphinx_exec_code/code_exec_error.py" = [
+    "PERF401",  # PERF401 Use a list comprehension to create a transformed list
+    "PLW2901",  # PLW2901 `for` loop variable `tb_line` overwritten by assignment target
+]
+
+
+[lint.isort]
+# https://docs.astral.sh/ruff/settings/#isort-lines-after-imports
+lines-after-imports = 2
+
+
+[lint.pylint]
+max-args = 6
diff --git a/doc/conf.py b/doc/conf.py
index f6f8d50..84afc91 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -10,15 +10,18 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
-import logging
+
 import os
 import sys
 
-# required for sphinx_exec_code
+
+# required for sphinx_exec_code to be found
 sys.path.insert(0, os.path.join(os.path.abspath('..'), 'src'))
 
+
 import sphinx_exec_code
 
+
 # -- Project information -----------------------------------------------------
 project = 'sphinx-exec-code'
 copyright = '2021, spacemanspiff2007'
diff --git a/requirements.txt b/requirements.txt
index 40e8301..bfdba37 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,7 @@
-pytest      >= 7.2,     < 7.3
-pre-commit  >= 3.0,     < 3.1
+pytest      == 7.4.4
+pre-commit  == 3.5.0
 
-sphinx              >= 6.1, < 6.2
-sphinx-rtd-theme    >= 1.2, <1.3
+ruff == 0.1.11
+
+sphinx           == 7.2.6
+sphinx-rtd-theme == 2.0.0
diff --git a/setup.py b/setup.py
index afcd1ae..d0f941a 100644
--- a/setup.py
+++ b/setup.py
@@ -46,7 +46,7 @@ def load_version() -> str:
     package_dir={'': 'src'},
     packages=find_packages('src', exclude=['tests*']),
     classifiers=[
-        "Development Status :: 4 - Beta",
+        "Development Status :: 5 - Production/Stable",
         'Intended Audience :: Developers',
         'Framework :: Sphinx :: Extension',
         "License :: OSI Approved :: Apache Software License",
@@ -56,6 +56,7 @@ def load_version() -> str:
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: 3 :: Only",
     ],
 )
diff --git a/src/sphinx_exec_code/__const__.py b/src/sphinx_exec_code/__const__.py
index f9da61c..770383c 100644
--- a/src/sphinx_exec_code/__const__.py
+++ b/src/sphinx_exec_code/__const__.py
@@ -1,3 +1,4 @@
 from sphinx.util import logging
 
+
 log = logging.getLogger('sphinx-exec-code')
diff --git a/src/sphinx_exec_code/__version__.py b/src/sphinx_exec_code/__version__.py
index 969399e..438a041 100644
--- a/src/sphinx_exec_code/__version__.py
+++ b/src/sphinx_exec_code/__version__.py
@@ -1 +1 @@
-__version__ = '0.10'
+__version__ = '0.11'
diff --git a/src/sphinx_exec_code/code_exec.py b/src/sphinx_exec_code/code_exec.py
index b2e9ac2..0b6251c 100644
--- a/src/sphinx_exec_code/code_exec.py
+++ b/src/sphinx_exec_code/code_exec.py
@@ -22,7 +22,7 @@ def execute_code(code: str, file: Path, first_loc: int) -> str:
             env['PYTHONPATH'] = os.pathsep.join(python_folders)
 
     run = subprocess.run([sys.executable, '-c', code.encode('utf-8')], capture_output=True, text=True,
-                         encoding=encoding, cwd=cwd, env=env)
+                         encoding=encoding, cwd=cwd, env=env, check=False)
 
     if run.returncode != 0:
         raise CodeExceptionError(code, file, first_loc, run.returncode, run.stderr) from None
diff --git a/src/sphinx_exec_code/code_exec_error.py b/src/sphinx_exec_code/code_exec_error.py
index 5ff4343..2bd4500 100644
--- a/src/sphinx_exec_code/code_exec_error.py
+++ b/src/sphinx_exec_code/code_exec_error.py
@@ -2,6 +2,7 @@
 from pathlib import Path
 from typing import List
 
+
 re_line = re.compile(r'^\s*File "(<string>)", line (\d+), in <module>', re.MULTILINE)
 
 
diff --git a/src/sphinx_exec_code/code_format.py b/src/sphinx_exec_code/code_format.py
index 94dcd22..697e97b 100644
--- a/src/sphinx_exec_code/code_format.py
+++ b/src/sphinx_exec_code/code_format.py
@@ -21,15 +21,15 @@ def __init__(self, marker: str):
     def is_marker(self, line: str) -> bool:
         if line == self.start:
             if not self.do_add:
-                raise VisibilityMarkerError(f'{self.start[1:]} already called! '
-                                            f'Use {self.stop[1:]} or {self.toggle[1:]}!')
+                msg = f'{self.start[1:]} already called! Use {self.stop[1:]} or {self.toggle[1:]}!'
+                raise VisibilityMarkerError(msg)
             self.do_add = False
             return True
 
         if line == self.stop:
             if self.do_add:
-                raise VisibilityMarkerError(f'{self.stop[1:]} already called! '
-                                            f'Use {self.start[1:]} or {self.toggle[1:]}!')
+                msg = f'{self.stop[1:]} already called! Use {self.start[1:]} or {self.toggle[1:]}!'
+                raise VisibilityMarkerError(msg)
             self.do_add = True
             self.skip_empty = True
             return True
diff --git a/src/sphinx_exec_code/configuration/base.py b/src/sphinx_exec_code/configuration/base.py
index d7672fd..854c971 100644
--- a/src/sphinx_exec_code/configuration/base.py
+++ b/src/sphinx_exec_code/configuration/base.py
@@ -5,6 +5,7 @@
 
 from sphinx_exec_code.__const__ import log
 
+
 TYPE_VALUE = TypeVar('TYPE_VALUE')
 
 
@@ -18,7 +19,8 @@ def __init__(self, sphinx_name: str, initial_value: Optional[TYPE_VALUE] = None)
     @property
     def value(self) -> TYPE_VALUE:
         if self._value is None:
-            raise ConfigError(f'{self.sphinx_name} is not set!')
+            msg = f'{self.sphinx_name} is not set!'
+            raise ConfigError(msg)
         return self._value
 
     def transform_value(self, app: SphinxApp, value):
@@ -40,5 +42,6 @@ def from_app(self, app: SphinxApp) -> TYPE_VALUE:
         self._value = self.validate_value(value)
         return self._value
 
-    def add_config_value(self, app: SphinxApp, sphinx_default):
+    def add_config_value(self, app: SphinxApp, sphinx_default: TYPE_VALUE):
+        self.validate_value(sphinx_default)
         app.add_config_value(self.sphinx_name, sphinx_default, 'env', self.SPHINX_TYPE)
diff --git a/src/sphinx_exec_code/configuration/flag_config.py b/src/sphinx_exec_code/configuration/flag_config.py
index fd075b7..2471e1c 100644
--- a/src/sphinx_exec_code/configuration/flag_config.py
+++ b/src/sphinx_exec_code/configuration/flag_config.py
@@ -6,5 +6,10 @@
 class SphinxConfigFlag(SphinxConfigValue[bool]):
     SPHINX_TYPE = bool
 
+    def validate_value(self, value) -> bool:
+        if not isinstance(value, bool):
+            raise TypeError()
+        return value
+
     def transform_value(self, app: SphinxApp, value) -> bool:
         return bool(value)
diff --git a/src/sphinx_exec_code/configuration/path_config.py b/src/sphinx_exec_code/configuration/path_config.py
index 31e9d6e..eb12d46 100644
--- a/src/sphinx_exec_code/configuration/path_config.py
+++ b/src/sphinx_exec_code/configuration/path_config.py
@@ -4,7 +4,7 @@
 from sphinx.application import Sphinx as SphinxApp
 
 from sphinx_exec_code.__const__ import log
-from sphinx_exec_code.configuration.base import SphinxConfigValue, TYPE_VALUE
+from sphinx_exec_code.configuration.base import TYPE_VALUE, SphinxConfigValue
 
 
 class InvalidPathError(Exception):
@@ -18,8 +18,9 @@ def make_path(self, app: SphinxApp, value) -> Path:
         try:
             path = Path(value)
         except Exception:
-            raise InvalidPathError(f'Could not create Path from "{value}" (type {type(value).__name__}) '
-                                   f'(configured by {self.sphinx_name:s})') from None
+            msg = (f'Could not create Path from "{value}" (type {type(value).__name__}) '
+                   f'(configured by {self.sphinx_name:s})')
+            raise InvalidPathError(msg) from None
 
         if not path.is_absolute():
             path = (Path(app.confdir) / path).resolve()
@@ -27,7 +28,8 @@ def make_path(self, app: SphinxApp, value) -> Path:
 
     def check_folder_exists(self, folder: Path) -> Path:
         if not folder.is_dir():
-            raise FileNotFoundError(f'Directory "{folder}" not found! (configured by {self.sphinx_name:s})')
+            msg = f'Directory "{folder}" not found! (configured by {self.sphinx_name:s})'
+            raise FileNotFoundError(msg)
         return folder
 
 
diff --git a/src/sphinx_exec_code/configuration/values.py b/src/sphinx_exec_code/configuration/values.py
index 2ebddad..16df932 100644
--- a/src/sphinx_exec_code/configuration/values.py
+++ b/src/sphinx_exec_code/configuration/values.py
@@ -1,6 +1,7 @@
 from .flag_config import SphinxConfigFlag
 from .path_config import SphinxConfigFolder, SphinxConfigMultipleFolderStr
 
+
 EXAMPLE_DIR = SphinxConfigFolder('exec_code_example_dir')
 
 # Options for code execution
diff --git a/src/sphinx_exec_code/sphinx_api.py b/src/sphinx_exec_code/sphinx_api.py
index f66370b..cd8c5f2 100644
--- a/src/sphinx_exec_code/sphinx_api.py
+++ b/src/sphinx_exec_code/sphinx_api.py
@@ -16,7 +16,6 @@ def builder_ready(app: SphinxApp):
     WORKING_DIR.from_app(app)
     PYTHONPATH_FOLDERS.from_app(app)
     SET_UTF8_ENCODING.from_app(app)
-    return None
 
 
 def setup(app):
@@ -33,7 +32,7 @@ def setup(app):
     EXAMPLE_DIR.add_config_value(app, confdir)
     WORKING_DIR.add_config_value(app, confdir.parent)
     PYTHONPATH_FOLDERS.add_config_value(app, code_folders)
-    SET_UTF8_ENCODING.add_config_value(app, True if os.name == 'nt' else False)  # Somehow this workaround is required
+    SET_UTF8_ENCODING.add_config_value(app, os.name == 'nt')
 
     app.connect('builder-inited', builder_ready)
     app.add_directive('exec_code', ExecCode)
diff --git a/src/sphinx_exec_code/sphinx_exec.py b/src/sphinx_exec_code/sphinx_exec.py
index a425e23..9d4c696 100644
--- a/src/sphinx_exec_code/sphinx_exec.py
+++ b/src/sphinx_exec_code/sphinx_exec.py
@@ -8,9 +8,9 @@
 
 from sphinx_exec_code.__const__ import log
 from sphinx_exec_code.code_exec import CodeExceptionError, execute_code
-from sphinx_exec_code.code_format import get_show_exec_code, VisibilityMarkerError
+from sphinx_exec_code.code_format import VisibilityMarkerError, get_show_exec_code
 from sphinx_exec_code.configuration import EXAMPLE_DIR
-from sphinx_exec_code.sphinx_spec import build_spec, SpecCode, SpecOutput, SphinxSpecBase
+from sphinx_exec_code.sphinx_spec import SpecCode, SpecOutput, SphinxSpecBase, build_spec
 
 
 def create_literal_block(objs: list, code: str, spec: SphinxSpecBase):
@@ -45,7 +45,7 @@ def run(self) -> list:
         try:
             return self._run()
         except ExtensionError as e:
-            raise e
+            raise e from None
         except Exception as e:
             name = self.__class__.__name__
             log.error(f'Error while running {name}!')
@@ -53,7 +53,9 @@ def run(self) -> list:
             if not isinstance(e, VisibilityMarkerError):
                 for line in traceback.format_exc().splitlines():
                     log.error(line)
-            raise ExtensionError(f'Error while running {name}!', orig_exc=e)
+
+            msg = f'Error while running {name}!'
+            raise ExtensionError(msg, orig_exc=e) from None
 
     def _get_code_line(self, line_no: int, content: List[str]) -> int:
         """Get the first line number of the code"""
@@ -63,7 +65,7 @@ def _get_code_line(self, line_no: int, content: List[str]) -> int:
         i = 0
         first_line = content[0]
 
-        for i, raw_line in enumerate(self.block_text.splitlines()):  # noqa: B007
+        for i, raw_line in enumerate(self.block_text.splitlines()):
             # raw line contains the leading white spaces
             if raw_line.lstrip() == first_line:
                 break
@@ -93,7 +95,8 @@ def _run(self) -> list:
         try:
             code_show, code_exec = get_show_exec_code(content)
         except Exception as e:
-            raise ExtensionError(f'Could not parse code markers at {self.get_location()}', orig_exc=e)
+            msg = f'Could not parse code markers at {self.get_location()}'
+            raise ExtensionError(msg, orig_exc=e) from None
 
         # Show the code from the user
         create_literal_block(output, code_show, spec=code_spec)
@@ -108,7 +111,8 @@ def _run(self) -> list:
             for line in e.pformat():
                 log.error(line)
 
-            raise ExtensionError('Could not execute code!') from None
+            msg = 'Could not execute code!'
+            raise ExtensionError(msg) from None
 
         # Show the output from the code execution
         create_literal_block(output, code_results, spec=SpecOutput.from_options(self.options))
diff --git a/src/sphinx_exec_code/sphinx_spec.py b/src/sphinx_exec_code/sphinx_spec.py
index 0bbbd9a..2218d8d 100644
--- a/src/sphinx_exec_code/sphinx_spec.py
+++ b/src/sphinx_exec_code/sphinx_spec.py
@@ -1,11 +1,11 @@
-from typing import Any, Callable, Dict
+from typing import Any, Callable, ClassVar, Dict
 
 from docutils.parsers.rst import directives  # type: ignore
 
 
 class SphinxSpecBase:
-    aliases: Dict[str, str]
-    defaults: Dict[str, str]
+    aliases: ClassVar[Dict[str, str]]
+    defaults: ClassVar[Dict[str, str]]
 
     def __init__(self, hide: bool, linenos: bool, caption: str, language: str):
         # flags
@@ -45,14 +45,14 @@ def build_spec() -> Dict[str, Callable[[Any], Any]]:
 
 
 class SpecCode(SphinxSpecBase):
-    aliases = {
+    aliases: ClassVar = {
         'hide_code': 'hide',
         'caption': 'caption',
         'language': 'language',
         'linenos': 'linenos',
         'filename': 'filename',
     }
-    defaults = {
+    defaults: ClassVar = {
         'caption': '',
         'language': 'python',
         'filename': '',
@@ -64,13 +64,13 @@ def __init__(self, hide: bool, linenos: bool, caption: str, language: str, filen
 
 
 class SpecOutput(SphinxSpecBase):
-    aliases = {
+    aliases: ClassVar = {
         'hide_output': 'hide',
         'caption_output': 'caption',
         'language_output': 'language',
         'linenos_output': 'linenos',
     }
-    defaults = {
+    defaults: ClassVar = {
         'caption': '',
         'language': 'none',
     }
diff --git a/tests/test_code_exec.py b/tests/test_code_exec.py
index 31a16f7..f7cdbf8 100644
--- a/tests/test_code_exec.py
+++ b/tests/test_code_exec.py
@@ -8,15 +8,15 @@
 
 
 @pytest.fixture()
-def setup_env(monkeypatch):
+def _setup_env(monkeypatch):
     f = Path(__file__).parent
     monkeypatch.setattr(WORKING_DIR, '_value', f)
     monkeypatch.setattr(PYTHONPATH_FOLDERS, '_value', [str(f)])
-    return None
 
 
 @pytest.mark.parametrize('utf8', [True, False])
-def test_print(setup_env, monkeypatch, utf8):
+@pytest.mark.usefixtures('_setup_env')
+def test_print(monkeypatch, utf8):
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', utf8)
 
     code = "print('Line1')\nprint('Line2')"
@@ -25,7 +25,8 @@ def test_print(setup_env, monkeypatch, utf8):
 
 
 @pytest.mark.parametrize('utf8', [True, False])
-def test_print_table(setup_env, monkeypatch, utf8):
+@pytest.mark.usefixtures('_setup_env')
+def test_print_table(monkeypatch, utf8):
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', utf8)
 
     code = "\n \n  \n\n" \
@@ -36,7 +37,8 @@ def test_print_table(setup_env, monkeypatch, utf8):
 
 
 @pytest.mark.parametrize('utf8', [True, False])
-def test_err(setup_env, monkeypatch, utf8):
+@pytest.mark.usefixtures('_setup_env')
+def test_err(monkeypatch, utf8):
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', utf8)
 
     code = "print('Line1')\nprint('Line2')\n1/0"
@@ -60,7 +62,8 @@ def test_err(setup_env, monkeypatch, utf8):
 
 
 @pytest.mark.skipif(not IS_WIN, reason='Windows only')
-def test_unicode_fails(setup_env, monkeypatch):
+@pytest.mark.usefixtures('_setup_env')
+def test_unicode_fails(monkeypatch):
     code = "print('●')"
 
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', False)
@@ -69,9 +72,13 @@ def test_unicode_fails(setup_env, monkeypatch):
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', True)
     assert execute_code(code, 'my_file', 1) == '●'
 
+    code = "print('This is a beautiful unicode character: \u265E.')"
+    assert execute_code(code, 'my_file', 1) == 'This is a beautiful unicode character: \u265E.'
+
 
 @pytest.mark.skipif(IS_WIN, reason='Fails on Windows')
-def test_unicode_no_utf8(setup_env, monkeypatch):
+@pytest.mark.usefixtures('_setup_env')
+def test_unicode_no_utf8(monkeypatch):
     code = "print('●')"
 
     monkeypatch.setattr(SET_UTF8_ENCODING, '_value', False)
diff --git a/tests/test_code_format.py b/tests/test_code_format.py
index a690f69..659a89f 100644
--- a/tests/test_code_format.py
+++ b/tests/test_code_format.py
@@ -1,6 +1,6 @@
 import pytest
 
-from sphinx_exec_code.code_format import get_show_exec_code, VisibilityMarkerError
+from sphinx_exec_code.code_format import VisibilityMarkerError, get_show_exec_code
 
 
 def test_format_hide():
diff --git a/tests/test_sphinx_spec.py b/tests/test_sphinx_spec.py
index 0d3cf2d..c2ec7bf 100644
--- a/tests/test_sphinx_spec.py
+++ b/tests/test_sphinx_spec.py
@@ -4,7 +4,7 @@
 import pytest
 from docutils.parsers.rst import directives
 
-from sphinx_exec_code.sphinx_spec import build_spec, SpecCode, SpecOutput, SphinxSpecBase
+from sphinx_exec_code.sphinx_spec import SpecCode, SpecOutput, SphinxSpecBase, build_spec
 
 
 def test_aliases_unique():
@@ -14,7 +14,7 @@ def test_aliases_unique():
         assert key_output not in SpecCode.aliases
 
 
-@pytest.mark.parametrize('cls', (SpecCode, SpecOutput))
+@pytest.mark.parametrize('cls', [SpecCode, SpecOutput])
 def test_default_in_aliases(cls: Type[SphinxSpecBase]):
     names = list(cls.aliases.values())
     for k in cls.defaults: