diff --git a/app/Http/Controllers/UserPreferencesController.php b/app/Http/Controllers/UserPreferencesController.php
index e742115c58..0347a21c0c 100644
--- a/app/Http/Controllers/UserPreferencesController.php
+++ b/app/Http/Controllers/UserPreferencesController.php
@@ -37,12 +37,6 @@ use Session;
 
 class UserPreferencesController extends Controller
 {
-    private $valid_prefs = [
-        'dashboard' => 'required|integer',
-        'add_schedule_note_to_device' => 'required|integer',
-        'locale' => 'required|in:en,ru',
-    ];
-
     public function __construct()
     {
         $this->middleware('deny-demo');
@@ -64,14 +58,9 @@ class UserPreferencesController extends Controller
             'default_dashboard' => UserPref::getPref($user, 'dashboard'),
             'note_to_device' => UserPref::getPref($user, 'add_schedule_note_to_device'),
             'locale' => UserPref::getPref($user, 'locale') ?: 'en',
+            'locales' => $this->getValidLocales(),
         ];
 
-        foreach (glob(resource_path('lang') . '/*', GLOB_ONLYDIR) as $locale) {
-            $locale = basename($locale);
-            $lang = __('preferences.lang', [], $locale);
-            $data['locales'][$locale] = ($lang == 'preferences.lang' ? $locale : $lang);
-        }
-
         if (Config::get('twofactor')) {
             $twofactor = UserPref::getPref($user, 'twofactor');
             if ($twofactor) {
@@ -90,14 +79,23 @@ class UserPreferencesController extends Controller
     /**
      * Store a newly created resource in storage.
      *
-     * @param  \Illuminate\Http\Request  $request
+     * @param \Illuminate\Http\Request $request
      * @return \Illuminate\Http\Response
      */
     public function store(Request $request)
     {
+        $valid_prefs = [
+            'dashboard' => 'required|integer',
+            'add_schedule_note_to_device' => 'required|integer',
+            'locale' => [
+                'required',
+                Rule::in(array_keys($this->getValidLocales())),
+            ],
+        ];
+
         $this->validate($request, [
-            'pref' => ['required', Rule::in(array_keys($this->valid_prefs))],
-            'value' => $this->valid_prefs[$request->pref] ?? 'required|integer',
+            'pref' => ['required', Rule::in(array_keys($valid_prefs))],
+            'value' => $valid_prefs[$request->pref] ?? 'required|integer',
         ]);
 
         UserPref::setPref($request->user(), $request->pref, $request->value);
@@ -108,4 +106,16 @@ class UserPreferencesController extends Controller
 
         return response()->json(['status' => 'success']);
     }
+
+    private function getValidLocales()
+    {
+        return array_reduce(glob(resource_path('lang') . '/*', GLOB_ONLYDIR), function ($locales, $locale) {
+            {
+                $locale = basename($locale);
+                $lang = __('preferences.lang', [], $locale);
+                $locales[$locale] = ($lang == 'preferences.lang' ? $locale : $lang);
+                return $locales;
+            }
+        }, []);
+    }
 }
diff --git a/resources/views/user/preferences.blade.php b/resources/views/user/preferences.blade.php
index dae9ab2adc..74127ba097 100644
--- a/resources/views/user/preferences.blade.php
+++ b/resources/views/user/preferences.blade.php
@@ -220,9 +220,17 @@
                         $this.closest('.form-group').removeClass('has-success');
                     }, 2000);
                 },
-                error: function () {
+                error: function (data) {
                     $this.val($this.data('previous'));
                     $this.closest('.form-group').addClass('has-error');
+
+                    var json = data.responseJSON;
+                    var errors = [];
+                    for (var attrib in json) {
+                        errors.push(json[attrib]);
+                    }
+                    toastr.error('Error: ' + errors.join("<br />"));
+
                     setTimeout(function(){
                         $this.closest('.form-group').removeClass('has-error');
                     }, 2000);