diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 014f7539..076bab24 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,23 +12,23 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-
-    - name: Validate composer.json and composer.lock
-      run: composer validate
-
-    - name: Cache Composer packages
-      id: composer-cache
-      uses: actions/cache@v2
-      with:
-        path: vendor
-        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
-        restore-keys: |
-          ${{ runner.os }}-php-
-
-    - name: Install dependencies
-      if: steps.composer-cache.outputs.cache-hit != 'true'
-      run: composer install --prefer-dist --no-progress --no-suggest
-
-    - name: Run PHPUnit
-      run: composer run-script test
+      - uses: actions/checkout@v2
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate
+
+      - name: Cache Composer packages
+        id: composer-cache
+        uses: actions/cache@v2
+        with:
+          path: vendor
+          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-php-
+
+      - name: Install dependencies
+        if: steps.composer-cache.outputs.cache-hit != 'true'
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Run PHPUnit
+        run: composer run-script test
\ No newline at end of file
diff --git a/.github/workflows/code-style.yml b/.github/workflows/code-style.yml
new file mode 100644
index 00000000..16ab9a56
--- /dev/null
+++ b/.github/workflows/code-style.yml
@@ -0,0 +1,25 @@
+name: Code style
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  phpcs:
+    name: PHPCS
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+
+      - name: Install dependencies
+        run: composer update --prefer-dist --no-progress --no-suggest
+
+      - name: Run script
+        run: vendor/bin/phpcs
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 96ccab44..8e409f4d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,7 @@
 .phan
 composer.lock
 
+/.phpcs-cache
+/phpcs.xml
+
 .phpunit.result.cache
\ No newline at end of file
diff --git a/composer.json b/composer.json
index d164a223..e3ca6e68 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,8 @@
     "phan/phan": "^2.7"
   },
   "require-dev": {
-    "phpunit/phpunit": "^9"
+    "phpunit/phpunit": "^9",
+    "squizlabs/php_codesniffer": "^3.7"
   },
   "scripts": {
     "test": "vendor/bin/phpunit tests"
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
new file mode 100644
index 00000000..15405496
--- /dev/null
+++ b/phpcs.xml.dist
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ruleset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/squizlabs/php_codesniffer/phpcs.xsd">
+
+    <arg name="extensions" value="php"/>
+    <rule ref="PSR12"/>
+
+    <file>.</file>
+</ruleset>