diff --git a/composer.json b/composer.json
index c6b6f5b..74eb036 100644
--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,7 @@
     "license": "GPL-3.0",
     "require": {
         "phpunit/php-text-template": "^1.0",
-        "phpunit/phpunit": "^8.0.0"
+        "phpunit/phpunit": "^9.0.0"
     },
     "autoload": {
         "files": [