diff --git a/composer.json b/composer.json
index 473a55d..76be61b 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
   "require": {
     "php": "^7.2|^8.0",
     "ext-json": "*",
-    "guzzlehttp/guzzle": "^7.3"
+    "guzzlehttp/guzzle": "^7.3|^6.5"
   },
   "require-dev": {
     "phpunit/phpunit": "^8|^9"