diff --git a/composer.json b/composer.json
index 09a1fa0..a18c55a 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
         "yiisoft/yii2-httpclient": "^2.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8.5",
+        "phpunit/phpunit": "^9.6",
         "rector/rector": "^1.0"
     },
     "autoload": {