diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ef6a2ab..ff66d9b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,13 +13,15 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  python:
-    if: ${{ (github.event_name == 'push' && startsWith(github.ref,'refs/heads/main')) || (github.event_name == 'pull_request' && github.event.pull_request.draft == false && contains(github.event.pull_request.labels.*.name,'ready')) }}
+  linux:
+    name: linux (py=${{ matrix.python-version }})
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.11','3.12']
+        python-version: ["3.11","3.12"]
+    env:
+      PYTHONPATH: src
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -31,3 +33,21 @@ jobs:
       - run: black --check .
       - run: pytest -q
       - run: mypy .
+
+  windows_optional:
+    name: windows (optional)
+    runs-on: windows-latest
+    continue-on-error: true
+    env:
+      PYTHONPATH: src
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - run: python -m pip install -U pip
+      - run: pip install ruff black pytest mypy
+      - run: ruff check .
+      - run: black --check .
+      - run: pytest -q
+      - run: mypy .
diff --git a/src/commit_guardian/__init__.py b/src/commit_guardian/__init__.py
index 61d8083..18a159d 100644
--- a/src/commit_guardian/__init__.py
+++ b/src/commit_guardian/__init__.py
@@ -1,5 +1,6 @@
 __all__ = ["ping", "__version__"]
 __version__ = "0.1.0"
 
+
 def ping() -> str:
     return "pong"
diff --git a/src/commit_guardian/cli.py b/src/commit_guardian/cli.py
index 1841125..2e95176 100644
--- a/src/commit_guardian/cli.py
+++ b/src/commit_guardian/cli.py
@@ -1,8 +1,8 @@
 from __future__ import annotations
-import sys
 import click
 from . import __version__, ping
 
+
 @click.command()
 @click.option("--version", is_flag=True, help="Show version and exit.")
 def main(version: bool) -> None:
@@ -12,5 +12,6 @@ def main(version: bool) -> None:
     click.echo(ping())
     raise SystemExit(0)
 
+
 if __name__ == "__main__":
     main()
diff --git a/tests/test_sanity.py b/tests/test_sanity.py
index 3d243a5..1963bc1 100644
--- a/tests/test_sanity.py
+++ b/tests/test_sanity.py
@@ -1,4 +1,5 @@
 import commit_guardian as cg
 
+
 def test_ping() -> None:
     assert cg.ping() == "pong"