diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 20e13db12b..ad8d3193b7 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -100,6 +100,7 @@ Yii Framework 2 Change Log
 - Enh #13268: Added logging of memory usage (bashkarev)
 - Enh: Added constants for specifying `yii\validators\CompareValidator::$type` (cebe)
 - Enh: Refactored `yii\web\ErrorAction` to make it reusable (silverfire)
+- Bug #13287: Fixed translating "and" separator in `UniqueValidator` error message (jetexe) 
 
 
 2.0.10 October 20, 2016
diff --git a/framework/helpers/BaseInflector.php b/framework/helpers/BaseInflector.php
index 4fb060de6c..4a8933c96a 100644
--- a/framework/helpers/BaseInflector.php
+++ b/framework/helpers/BaseInflector.php
@@ -566,8 +566,11 @@ class BaseInflector
      * @return string the generated sentence
      * @since 2.0.1
      */
-    public static function sentence(array $words, $twoWordsConnector = ' and ', $lastWordConnector = null, $connector = ', ')
+    public static function sentence(array $words, $twoWordsConnector = null, $lastWordConnector = null, $connector = ', ')
     {
+        if ($twoWordsConnector === null) {
+            $twoWordsConnector = Yii::t('yii', ' and ');
+        }
         if ($lastWordConnector === null) {
             $lastWordConnector = $twoWordsConnector;
         }
diff --git a/framework/messages/ru/yii.php b/framework/messages/ru/yii.php
index 936c889b15..b1aa070d63 100644
--- a/framework/messages/ru/yii.php
+++ b/framework/messages/ru/yii.php
@@ -21,6 +21,7 @@ return [
     'Unknown alias: -{name}' => 'Неизвестный псевдоним: -{name}',
     'Yii Framework' => 'Yii Framework',
     '(not set)' => '(не задано)',
+    ' and ' => ' и ',
     'An internal server error occurred.' => 'Возникла внутренняя ошибка сервера.',
     'Are you sure you want to delete this item?' => 'Вы уверены, что хотите удалить этот элемент?',
     'Error' => 'Ошибка',