diff --git a/src/Orchard.Web/Modules/Orchard.Users/Controllers/AccountController.cs b/src/Orchard.Web/Modules/Orchard.Users/Controllers/AccountController.cs
index 6de70a07f..685f496a9 100644
--- a/src/Orchard.Web/Modules/Orchard.Users/Controllers/AccountController.cs
+++ b/src/Orchard.Web/Modules/Orchard.Users/Controllers/AccountController.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
-using System.Globalization;
 using System.Security.Principal;
 using System.Web.Mvc;
 using System.Web.Security;
diff --git a/src/Orchard.Web/Modules/Orchard.Users/Controllers/AdminController.cs b/src/Orchard.Web/Modules/Orchard.Users/Controllers/AdminController.cs
index 3502f0449..e85de7d77 100644
--- a/src/Orchard.Web/Modules/Orchard.Users/Controllers/AdminController.cs
+++ b/src/Orchard.Web/Modules/Orchard.Users/Controllers/AdminController.cs
@@ -2,7 +2,6 @@ using System.Linq;
 using System.Web.Mvc;
 using Orchard.ContentManagement;
 using Orchard.Localization;
-using Orchard.Mvc.Extensions;
 using Orchard.Security;
 using Orchard.UI.Notify;
 using Orchard.Users.Drivers;
@@ -71,11 +70,11 @@ namespace Orchard.Users.Controllers {
 
             string userExistsMessage = _userService.VerifyUserUnicity(model.UserName, model.Email);
             if (userExistsMessage != null) {
-                ModelState.AddModelError("NotUniqueUserName", T(userExistsMessage));
+                AddModelError("NotUniqueUserName", T(userExistsMessage));
             }
 
             if (model.Password != model.ConfirmPassword) {
-                ModelState.AddModelError("ConfirmPassword", T("Password confirmation must match"));
+                AddModelError("ConfirmPassword", T("Password confirmation must match"));
             }
 
             user = _membershipService.CreateUser(new CreateUserParams(
@@ -123,7 +122,7 @@ namespace Orchard.Users.Controllers {
 
             string userExistsMessage = _userService.VerifyUserUnicity(id, model.UserName, model.Email);
             if (userExistsMessage != null) {
-                ModelState.AddModelError("NotUniqueUserName", T(userExistsMessage));
+                AddModelError("NotUniqueUserName", T(userExistsMessage));
             }
 
             if (!ModelState.IsValid) {
@@ -148,6 +147,10 @@ namespace Orchard.Users.Controllers {
         bool IUpdateModel.TryUpdateModel<TModel>(TModel model, string prefix, string[] includeProperties, string[] excludeProperties) {
             return TryUpdateModel(model, prefix, includeProperties, excludeProperties);
         }
+
+        public void AddModelError(string key, LocalizedString errorMessage) {
+            ModelState.AddModelError(key, errorMessage.ToString());
+        }
     }
 
 }