diff --git a/composer.json b/composer.json
index 20ac4c2..2924f64 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         "php": ">=7.4"
     },
     "require-dev": {
-
+        "phpunit/phpunit": "^9.5"
     },
     "autoload": {
         "psr-4": {