diff --git a/.gitignore b/.gitignore
index 59e2f7db..1591d558 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,7 +6,7 @@ coverage
 .project
 .settings
 .php_cs
-.php_cs.cache
+.php-cs-fixer.cache
 composer.lock
 docs-api
 phpunit.xml
diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index df516fb8..5edb9296 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -2,7 +2,7 @@
 
 $finder = new PhpCsFixer\Finder();
 $config = new PhpCsFixer\Config('json-schema');
-$finder->in(__DIR__);
+$finder->in([__DIR__ . '/src', __DIR__ . '/tests']);
 
 /* Based on ^2.1 of php-cs-fixer */
 $config
diff --git a/composer.json b/composer.json
index bbeca2f7..0befa020 100644
--- a/composer.json
+++ b/composer.json
@@ -33,7 +33,7 @@
         "icecave/parity": "^3.0"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "~2.2.20 || ~2.19.0",
+        "friendsofphp/php-cs-fixer": "3.3.0",
         "json-schema/json-schema-test-suite": "1.2.0",
         "phpunit/phpunit": "^8.5",
         "phpspec/prophecy": "^1.19",