diff --git a/composer.json b/composer.json
index d9e7346..5b3a76b 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
     "require-dev": {
         "squizlabs/php_codesniffer": "^3.0",
         "cambis/silverstan": "^2.0",
-        "phpunit/phpunit": "^11.0"
+        "phpunit/phpunit": "^13.0"
     },
     "keywords": [
         "silverstripe metadata",