diff --git a/composer.json b/composer.json
index 538ccb9..f901121 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
 	],
 	"require": {
 		"php": ">=5.3",
-		"guzzlehttp/guzzle": "~3.7"
+		"guzzlehttp/guzzle": "~3.7|^4.0|^5.0|^6.0|^7.0"
 	},
 	"require-dev": {
 		"phpunit/phpunit": "^4.8"