diff --git a/app/serializers/user_serializer.rb b/app/serializers/user_serializer.rb
index ff5cbb1f424a39b46c567f905f21a8d504f2246c..ff9a7dc7addafbb17f0192b1437b6cc7be4ac64d 100644
--- a/app/serializers/user_serializer.rb
+++ b/app/serializers/user_serializer.rb
@@ -1,4 +1,3 @@
-
 # Copyright (C) 2015 Centro de Computacao Cientifica e Software Livre
 # Departamento de Informatica - Universidade Federal do Parana
 #
@@ -37,7 +36,9 @@ class UserSerializer < ActiveModel::Serializer
   end
 
   def role_ids
-    object.roles.all.ids
+    roles = []
+    object.roles.each { |role| roles << role.id }
+    roles
   end
 
   attributes \