diff --git a/composer.json b/composer.json
index 49e6ade..d850867 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
     "require-dev": {
         "phpmd/phpmd": "^2.9",
         "phpstan/phpstan": "^0.12",
-        "phpunit/phpunit": "^8.5",
+        "phpunit/phpunit": "^9.5",
         "squizlabs/php_codesniffer": "^3.5"
     },
     "autoload": {