diff --git a/composer.json b/composer.json
index 7b00dd4..cc28df5 100644
--- a/composer.json
+++ b/composer.json
@@ -13,8 +13,8 @@
         }
     ],
     "require": {
-        "php" : ">=5.5",
-        "league/oauth2-client": "^1.4"
+        "php" : ">=5.6",
+        "league/oauth2-client": "^2.0"
     },
     "require-dev": {
         "phpunit/phpunit" : "~4.6",