diff --git a/composer.json b/composer.json
index 8d90b04..8d05d54 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
     "robmorgan/phinx": "^0.12.11",
     "symfony/yaml": "^5.4 || ^7.0",
     "vlucas/phpdotenv": "^5.4",
-    "wyrihaximus/async-test-utilities": "^8.0.1"
+    "wyrihaximus/async-test-utilities": "^8.0.1 || ^9.0.0"
   },
   "autoload": {
     "psr-4": {