diff --git a/composer.json b/composer.json
index 0889892..0096f5e 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
     }
   },
   "require-dev": {
-    "phpunit/phpunit": "^8.0",
+    "phpunit/phpunit": "^9.5",
     "phpstan/phpstan": "^0.12.14",
     "broadway/coding-standard": "^1.2"
   }