diff --git a/lib/Auth/OAuth.php b/lib/Auth/OAuth.php
index b073491f..fc963560 100755
--- a/lib/Auth/OAuth.php
+++ b/lib/Auth/OAuth.php
@@ -592,7 +592,7 @@ protected function prepareRequest($url, array $headers, array $parameters, $meth
             //OAuth 2.0
             $this->log('making request using OAuth2 spec');
 
-            $parameters['access_token'] = $this->_access_token;
+            $headers[] = 'Authorization: Bearer '.$this->_access_token;
         }
 
         return [$headers, $parameters];