diff --git a/composer.json b/composer.json
index b3a22fa..a2dfb55 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
         "php": ">=7.0.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~6.0 || ~7.0 || ~9.0"
+        "phpunit/phpunit": "~11.0"
     },
     "suggest": {
         "ext-intl": "Use Intl for transliterator_transliterate() support"