diff --git a/lib/user-methods.js b/lib/user-methods.js
index 03363026..7994d71d 100644
--- a/lib/user-methods.js
+++ b/lib/user-methods.js
@@ -28,7 +28,7 @@ function node_require(module) {
 function checkTypes(args, types) {
     args = Array.prototype.slice.call(args);
     for (var i = 0; i < types.length; ++i) {
-        if (typeof args[i] !== types[i]) {
+        if (args.length > i && typeof args[i] !== types[i]) {
             throw new TypeError('param ' + i + ' must be of type ' + types[i]);
         }
     }
@@ -154,7 +154,7 @@ const staticMethods = {
         },
 
         adminUser(token, server) {
-            checkTypes(arguments, ['string']);
+            checkTypes(arguments, ['string', 'string']);
             const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
                 var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
                 return v.toString(16);