diff --git a/composer.json b/composer.json
index 2cb8318..780ca46 100644
--- a/composer.json
+++ b/composer.json
@@ -24,6 +24,7 @@
     "require-dev": {
         "enlightn/security-checker": "^1.10",
         "guzzlehttp/guzzle": "^6.5.8 || ^7.4.5",
+        "guzzlehttp/psr7": "^1.9.1 || ^2.4.5",
         "phpunit/phpunit": "^9.0",
         "symfony/mailer": "^6.0"
     },