diff --git a/composer.json b/composer.json
index 48700fe..5a4c624 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
     "tedivm/jshrink": "^1.8.1"
   },
   "require-dev": {
-    "phpunit/phpunit": "~6.0 || ~7.0 || ~8.0 || ~9.0"
+    "phpunit/phpunit": "~13.0"
   },
   "autoload": {
     "psr-4": {