diff --git a/composer.json b/composer.json
index 959f14a..14af243 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
     "require-dev": {
         "google/cloud-tools": "dev-main",
         "squizlabs/php_codesniffer": "^3.5",
-        "phpunit/phpunit": "^10.0",
+        "phpunit/phpunit": "^13.0",
         "friendsofphp/php-cs-fixer": "^3.46"
     },
     "autoload": {