diff --git a/composer.json b/composer.json
index d128ea5..a6e72c3 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "php": "^7.4 || ^8.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8 || ^9",
+        "phpunit/phpunit": "^9",
         "phpstan/phpstan": "^2",
         "phpstan/phpstan-strict-rules": "^2",
         "phpstan/phpstan-deprecation-rules": "^2"