diff --git a/composer.json b/composer.json
index 000e278..0e04308 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
         "elephox/mimey": "^4.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9",
+        "phpunit/phpunit": "^13",
         "codeception/specify": "^2.0.0"
     },
     "autoload": {