diff --git a/src/lib/api_elements/auth.js b/src/lib/api_elements/auth.js
index d4bb89f..1355709 100644
--- a/src/lib/api_elements/auth.js
+++ b/src/lib/api_elements/auth.js
@@ -154,6 +154,7 @@ authPrototypeMethods.requestTokenByPassword = function (username, password) {
         },
         body: [
             "client_id=" + this.options.key,
+            "client_secret=" + this.options.client_secret,
             "grant_type=password",
             "username=" + encodeURIComponent(username),
             "password=" + encodeURIComponent(password)
@@ -221,4 +222,4 @@ authPrototypeMethods.getUserInfo = function () {
 
 Auth.prototype = authPrototypeMethods;
 
-module.exports = Auth;
\ No newline at end of file
+module.exports = Auth;