diff --git a/.github/workflows/code-style.yml b/.github/workflows/code-style.yml
new file mode 100644
index 0000000..9e8dd7c
--- /dev/null
+++ b/.github/workflows/code-style.yml
@@ -0,0 +1,42 @@
+name: PHP-CS-Fixer
+
+on:
+    push:
+        branches: [ master, main ]
+    pull_request:
+        branches: [ master, main ]
+
+permissions:
+    contents: read
+
+jobs:
+    code-style:
+
+        runs-on: ubuntu-latest
+        permissions:
+            contents: write  # for Git to git apply
+
+        steps:
+            -   uses: actions/checkout@v3
+
+            -   name: Setup PHP
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: '8.3'
+                    extensions: gd, intl, pdo_mysql
+                    coverage: none # disable xdebug, pcov
+
+            # install dependencies from composer.json
+            -   name: Install test dependencies
+                env:
+                    COMPOSER: composer.json
+                run: composer install --prefer-dist --no-progress
+
+            # run php-cs-fixer, fix code styles
+            -   name: Run PHP CS Fixer
+                run: composer cs-fix
+
+            # commit and push fixed files
+            -   uses: stefanzweifel/git-auto-commit-action@v4
+                with:
+                    commit_message: Apply php-cs-fixer changes
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..e8dda5e
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,14 @@
+{
+  "require-dev": {
+    "redaxo/php-cs-fixer-config": "^2.0",
+    "friendsofphp/php-cs-fixer": "^3.14"
+  },
+  "replace": {
+    "psr/log": "*",
+    "psr/container": "*"
+  },
+  "scripts": {
+    "cs-dry": "php-cs-fixer fix -v --ansi --dry-run --config=.php-cs-fixer.dist.php",
+    "cs-fix": "php-cs-fixer fix -v --ansi --config=.php-cs-fixer.dist.php"
+  }
+}