diff --git a/composer.json b/composer.json
index 4b779c5..b5a5a1d 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,7 @@
     ],
     "require": {
         "php": "^5.5 || ^7.0",
-        "guzzlehttp/guzzle": "^6.0"
+        "guzzlehttp/guzzle": "^6.0|^7.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^5.7"