diff --git a/lib/oauth2.js b/lib/oauth2.js
index 94ed662c..91a51218 100644
--- a/lib/oauth2.js
+++ b/lib/oauth2.js
@@ -169,7 +169,8 @@ exports.OAuth2.prototype.getOAuthAccessToken= function(code, params, callback) {
 
   var post_data= querystring.stringify( params );
   var post_headers= {
-       'Content-Type': 'application/x-www-form-urlencoded'
+       'Content-Type': 'application/x-www-form-urlencoded',
+       'Authorization': 'Basic ' + new Buffer(this._clientId + ':' + this._clientSecret).toString('base64')
    };