diff --git a/composer.json b/composer.json
index efef696..a9e128e 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
     "description": "A PHP library for obtaining Trustpilot API access tokens",
     "require": {
         "php": ">=5.5.0",
-        "guzzlehttp/guzzle": "~6.0"
+        "guzzlehttp/guzzle": "~6.0 | ^7.0"
     },
     "license": "MIT",
     "authors": [