diff --git a/backend/__init__.py b/backend/__init__.py
index 63024b2..645ef81 100644
--- a/backend/__init__.py
+++ b/backend/__init__.py
@@ -1,6 +1,7 @@
 """
 Self-hosted backend for self-build (bootstrap).
 """
+
 from .wheel import build_wheel
 from .sdist import build_sdist
 
diff --git a/backend/sdist.py b/backend/sdist.py
index 0179605..3f52030 100644
--- a/backend/sdist.py
+++ b/backend/sdist.py
@@ -10,6 +10,7 @@
    - include *.py for now
    - exclude __pycache__ and .pyc
 """
+
 from io import BytesIO
 from pathlib import Path
 import logging
diff --git a/backend/wheel.py b/backend/wheel.py
index 71063c5..c58a6a5 100644
--- a/backend/wheel.py
+++ b/backend/wheel.py
@@ -10,6 +10,7 @@
    - include *.py for now
    - exclude __pycache__ and .pyc
 """
+
 from base64 import urlsafe_b64encode
 from io import TextIOWrapper, BytesIO
 from pathlib import Path
diff --git a/src/pyproject_installer/__main__.py b/src/pyproject_installer/__main__.py
index 641a632..3c9e0f5 100644
--- a/src/pyproject_installer/__main__.py
+++ b/src/pyproject_installer/__main__.py
@@ -11,6 +11,7 @@
     - RECORD is dropped (PEP627)
     - signature verification of signed wheel is not supported
 """
+
 from pathlib import Path
 import argparse
 import json
diff --git a/src/pyproject_installer/lib/backend_helper/backend_caller.py b/src/pyproject_installer/lib/backend_helper/backend_caller.py
index c77e249..189690b 100644
--- a/src/pyproject_installer/lib/backend_helper/backend_caller.py
+++ b/src/pyproject_installer/lib/backend_helper/backend_caller.py
@@ -2,6 +2,7 @@
 Intended to be run in subprocess to call build backend's hooks.
 Must not have dependencies other than stdlib.
 """
+
 from importlib import import_module
 from pathlib import Path
 import argparse
diff --git a/tests/integration/test_buildable.py b/tests/integration/test_buildable.py
index 3799c57..cac9324 100644
--- a/tests/integration/test_buildable.py
+++ b/tests/integration/test_buildable.py
@@ -1,6 +1,7 @@
 """
 Check if pyproject_installer is buildable by other tools like `build` or `pip`
 """
+
 import subprocess
 
 
diff --git a/tests/unit/test_build/test_pyproject_parser.py b/tests/unit/test_build/test_pyproject_parser.py
index 2810ffd..c99a4d8 100644
--- a/tests/unit/test_build/test_pyproject_parser.py
+++ b/tests/unit/test_build/test_pyproject_parser.py
@@ -1,4 +1,5 @@
 """Tests for parser of pyproject.toml"""
+
 import json
 import textwrap
 import sys
diff --git a/tests/unit/test_install/test_installer.py b/tests/unit/test_install/test_installer.py
index 600eff4..82df631 100644
--- a/tests/unit/test_install/test_installer.py
+++ b/tests/unit/test_install/test_installer.py
@@ -338,9 +338,9 @@ def test_data_invalid_scheme_key(wheel_contents, wheel, installed_wheel):
 @pytest.mark.parametrize("ep_spec", ("foo", "foo.bar"))
 def test_invalid_entry_points(ep_spec, wheel_contents, wheel, installed_wheel):
     contents = wheel_contents()
-    contents[
-        "foo-1.0.dist-info/entry_points.txt"
-    ] = f"[console_scripts]\nbar = {ep_spec}\n"
+    contents["foo-1.0.dist-info/entry_points.txt"] = (
+        f"[console_scripts]\nbar = {ep_spec}\n"
+    )
     with pytest.raises(ValueError, match="Invalid entry_points specification"):
         install_wheel(
             wheel(contents=contents), destdir=installed_wheel().destdir
@@ -414,9 +414,9 @@ def test_installation_filelist(
     strip_dist_info, wheel_contents, wheel, installed_wheel
 ):
     contents = wheel_contents()
-    contents[
-        "foo-1.0.dist-info/entry_points.txt"
-    ] = "[console_scripts]\nbar = foo:main\n"
+    contents["foo-1.0.dist-info/entry_points.txt"] = (
+        "[console_scripts]\nbar = foo:main\n"
+    )
 
     dest_wheel = installed_wheel()
     kwargs = {"destdir": dest_wheel.destdir}
@@ -552,9 +552,9 @@ def test_entry_points_scripts(
         "pyproject_installer.install_cmd._install.sys.executable", sys_exec
     )
     contents = wheel_contents()
-    contents[
-        "foo-1.0.dist-info/entry_points.txt"
-    ] = "[console_scripts]\nbar = foo:main\n"
+    contents["foo-1.0.dist-info/entry_points.txt"] = (
+        "[console_scripts]\nbar = foo:main\n"
+    )
 
     dest_wheel = installed_wheel()
 
diff --git a/tests/unit/test_run/test_env.py b/tests/unit/test_run/test_env.py
index 0ede743..b8ca17f 100644
--- a/tests/unit/test_run/test_env.py
+++ b/tests/unit/test_run/test_env.py
@@ -52,9 +52,9 @@ def main():
                     print("Hello, World! ({script_name})")
             """
         )
-        contents[
-            f"{contents.distinfo}/entry_points.txt"
-        ] = f"[console_scripts]\n{script_name} = {distr}:main\n"
+        contents[f"{contents.distinfo}/entry_points.txt"] = (
+            f"[console_scripts]\n{script_name} = {distr}:main\n"
+        )
 
         return wheel(name=f"{distr}-1.0-py3-none-any.whl", contents=contents)
 
diff --git a/tools/vendored.py b/tools/vendored.py
index 933c71a..798012b 100644
--- a/tools/vendored.py
+++ b/tools/vendored.py
@@ -13,6 +13,7 @@
 - packaging: https://github.com/pypa/packaging
 git diff 23.1:src/packaging @:src/pyproject_installer/_vendor/packaging
 """
+
 from pathlib import Path
 import sys
 import subprocess