diff --git a/.php-cs-fixer.php b/.php-cs-fixer.php
index 255fbfd4..9c69bbb6 100644
--- a/.php-cs-fixer.php
+++ b/.php-cs-fixer.php
@@ -26,9 +26,13 @@
 
 $license->save();
 
-$config = PhpCsFixer\Config\Factory::fromRuleSet(new PhpCsFixer\Config\RuleSet\Php81($license->header()), [
-    'mb_str_functions' => false,
-]);
+$ruleSet = PhpCsFixer\Config\RuleSet\Php81::create()
+    ->withHeader($license->header())
+    ->withRules(PhpCsFixer\Config\Rules::fromArray([
+        'mb_str_functions' => false,
+    ]));
+
+$config = PhpCsFixer\Config\Factory::fromRuleSet($ruleSet);
 
 $config->getFinder()
     ->exclude([
diff --git a/composer.json b/composer.json
index 3a5b9d56..2f24a512 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
     "ergebnis/composer-normalize": "^2.37.0",
     "ergebnis/data-provider": "^3.0.0",
     "ergebnis/license": "^2.2.0",
-    "ergebnis/php-cs-fixer-config": "^5.16.0",
+    "ergebnis/php-cs-fixer-config": "^6.0.0",
     "fakerphp/faker": "^1.23.0",
     "psalm/plugin-phpunit": "~0.18.4",
     "rector/rector": "~0.18.3",
diff --git a/composer.lock b/composer.lock
index 482f9aaa..29c34f61 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "1f3d3a27f19a0571cbf3d11be04239fa",
+    "content-hash": "3517ae9d7e0bcefa3b496c77b07c7143",
     "packages": [
         {
             "name": "myclabs/deep-copy",
@@ -2673,16 +2673,16 @@
         },
         {
             "name": "ergebnis/php-cs-fixer-config",
-            "version": "5.16.0",
+            "version": "6.0.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/ergebnis/php-cs-fixer-config.git",
-                "reference": "227631ebd63e1eae63805a0ffc711dac45e3c7df"
+                "reference": "36408450f5c17d35fafc815ff55d60b8fd520644"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/ergebnis/php-cs-fixer-config/zipball/227631ebd63e1eae63805a0ffc711dac45e3c7df",
-                "reference": "227631ebd63e1eae63805a0ffc711dac45e3c7df",
+                "url": "https://api.github.com/repos/ergebnis/php-cs-fixer-config/zipball/36408450f5c17d35fafc815ff55d60b8fd520644",
+                "reference": "36408450f5c17d35fafc815ff55d60b8fd520644",
                 "shasum": ""
             },
             "require": {
@@ -2691,14 +2691,14 @@
                 "php": "~8.1.0 || ~8.2.0"
             },
             "require-dev": {
-                "ergebnis/composer-normalize": "^2.36.0",
-                "ergebnis/license": "^2.1.0",
+                "ergebnis/composer-normalize": "^2.37.0",
+                "ergebnis/data-provider": "^3.0.0",
+                "ergebnis/license": "^2.2.0",
                 "ergebnis/phpunit-slow-test-detector": "^2.3.0",
                 "fakerphp/faker": "^1.23.0",
-                "infection/infection": "~0.27.0",
-                "phpunit/phpunit": "^10.3.3",
+                "phpunit/phpunit": "^10.3.4",
                 "psalm/plugin-phpunit": "~0.18.4",
-                "rector/rector": "~0.18.2",
+                "rector/rector": "~0.18.3",
                 "symfony/filesystem": "^5.0.0 || ^6.0.0",
                 "symfony/process": "^5.0.0 || ^6.0.0",
                 "vimeo/psalm": "^5.15.0"
@@ -2731,7 +2731,7 @@
                 "issues": "https://github.com/ergebnis/php-cs-fixer-config/issues",
                 "source": "https://github.com/ergebnis/php-cs-fixer-config"
             },
-            "time": "2023-09-18T05:53:54+00:00"
+            "time": "2023-09-18T14:28:24+00:00"
         },
         {
             "name": "fakerphp/faker",