diff --git a/composer.json b/composer.json
index 7b7e205..d3c8341 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
         "react-parallel/event-loop": "^2.0.0",
         "react/event-loop": "^1.5",
         "react/promise": "^2.9 || ^3.1",
-        "wyrihaximus/async-test-utilities": "^5 || ^7.2",
+        "wyrihaximus/async-test-utilities": "^5 || ^7.2 || ^9.0",
         "wyrihaximus/pool-info": "^1.1 || ^2.0"
     },
     "autoload": {