diff --git a/.vscode/settings.json b/.vscode/settings.json
index f774d18..e4cad61 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,6 +1,6 @@
 {
   "[python]": {
-    "editor.defaultFormatter": "ms-python.autopep8",
+    "editor.defaultFormatter": "charliermarsh.ruff",
     "editor.formatOnSave": true
   },
   "python.testing.pytestArgs": ["test"],
diff --git a/ruff.toml b/ruff.toml
new file mode 100644
index 0000000..eb329ee
--- /dev/null
+++ b/ruff.toml
@@ -0,0 +1,33 @@
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".bzr",
+    ".direnv",
+    ".eggs",
+    ".git",
+    ".git-rewrite",
+    ".hg",
+    ".ipynb_checkpoints",
+    ".mypy_cache",
+    ".nox",
+    ".pants.d",
+    ".pyenv",
+    ".pytest_cache",
+    ".pytype",
+    ".ruff_cache",
+    ".svn",
+    ".tox",
+    ".venv",
+    ".vscode",
+    "__pypackages__",
+    "_build",
+    "buck-out",
+    "build",
+    "dist",
+    "node_modules",
+    "site-packages",
+    "venv",
+]
+
+# Same as Black.
+line-length = 120
+indent-width = 4