diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index ad6415b..1aea071 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -21,7 +21,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Style checks
         run: |
-          pip install -U ruff
+          pip install -U ".[dev]"
           python -m ruff check .
       - name: Test suite run
         run: |
diff --git a/pyproject.toml b/pyproject.toml
index ca82d80..c2ad9b6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,6 +31,11 @@ content-type = "text/x-rst"
 Homepage = "https://www.breezy-vcs.org/"
 GitHub = "https://github.com/breezy-team/merge3"
 
+[project.optional-dependencies]
+"dev" = [
+    "ruff==0.4.3"
+]
+
 [tool.setuptools]
 packages = ["merge3"]
 include-package-data = false