diff --git a/2021/php/composer.json b/2021/php/composer.json
index 9fbf0c7..4fb6e44 100644
--- a/2021/php/composer.json
+++ b/2021/php/composer.json
@@ -2,7 +2,7 @@
     "name": "codelicia/aoc2021",
     "type": "project",
     "require-dev": {
-        "phpunit/phpunit": "11.0.x"
+        "phpunit/phpunit": "12.5.x"
     },
     "license": "MIT",
     "autoload": {