diff --git a/composer.json b/composer.json
index daa0bcf..61a3c6a 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
     "sabre/vobject": "^5.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^12.0"
+    "phpunit/phpunit": "^13.0"
   },
   "autoload": {
     "psr-4": {