diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 6f719ea2f8..2011c0f31a 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -25,7 +25,7 @@ Yii Framework 2 Change Log
 - Enh #2264: `CookieCollection::has()` will return false for expired or removed cookies (qiangxue)
 - Enh #2837: Error page now shows arguments in stack trace method calls (samdark)
 - Enh #2906: Added support for using conditional comments for js and css files registered through asset bundles and Html helper (exromany, qiangxue)
-- Enh #2942: Added truncate and truncateWord methods (Alex-Code)
+- Enh #2942: Added truncate and truncateWord methods (Alex-Code, samdark)
 - Enh #3008: Added `Html::errorSummary()` (qiangxue)
 - Enh #3088: The debug and gii modules will manage their own URL rules now (hiltonjanfield, qiangxue)
 - Enh #3103: debugger panel is now not displayed when printing a page (githubjeka)
diff --git a/framework/helpers/BaseStringHelper.php b/framework/helpers/BaseStringHelper.php
index e8bf4ff539..180d260b6e 100644
--- a/framework/helpers/BaseStringHelper.php
+++ b/framework/helpers/BaseStringHelper.php
@@ -89,11 +89,12 @@ class BaseStringHelper
     }
     
     /**
-     * Truncates a string to the specified length.
+     * Truncates a string to the number of characters specified.
+     *
      * @param string $string The string to truncate.
-     * @param integer $length The new length of the string.
-     * @param string $suffix A value to affix to the end.
-     * @param string $encoding The charset to use, defaults to application current.
+     * @param integer $length How many characters from original string to include into truncated string.
+     * @param string $suffix String to append to the end of truncated string.
+     * @param string $encoding The charset to use, defaults to charset currently used by application.
      * @return string the truncated string.
      */
     public static function truncate($string, $length, $suffix = '...', $encoding = null)
@@ -106,10 +107,11 @@ class BaseStringHelper
     }
     
     /**
-     * Split a string into words preserving whitespace and return the specified amount of words.
+     * Truncates a string to the number of words specified.
+     *
      * @param string $string The string to truncate.
-     * @param integer $count How many words to truncate to.
-     * @param string $suffix A value to affix to the end.
+     * @param integer $count How many words from original string to include into truncated string.
+     * @param string $suffix String to append to the end of truncated string.
      * @return string the truncated string.
      */
     public static function truncateWords($string, $count, $suffix = '...')
diff --git a/tests/unit/framework/helpers/StringHelperTest.php b/tests/unit/framework/helpers/StringHelperTest.php
index f1490edb05..4f9a50cd1d 100644
--- a/tests/unit/framework/helpers/StringHelperTest.php
+++ b/tests/unit/framework/helpers/StringHelperTest.php
@@ -10,6 +10,12 @@ use yiiunit\TestCase;
  */
 class StringHelperTest extends TestCase
 {
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->mockApplication();
+    }
+
     public function testStrlen()
     {
         $this->assertEquals(4, StringHelper::byteLength('this'));
@@ -68,16 +74,16 @@ class StringHelperTest extends TestCase
     
     public function testTruncate()
     {
-        $this->assertEquals('string test', StringHelper::truncate('string test', 20));
-        $this->assertEquals('string...', StringHelper::truncate('string test', 6));
-        $this->assertEquals('string!!!', StringHelper::truncate('string test', 6, '!!!'));
+        $this->assertEquals('привет, я multibyte...', StringHelper::truncate('привет, я multibyte строка!', 20));
+        $this->assertEquals('Не трогаем строку', StringHelper::truncate('Не трогаем строку', 20));
+        $this->assertEquals('исполь!!!', StringHelper::truncate('используем восклицательные знаки', 6, '!!!'));
     }
     
     public function testTruncateWords()
     {
-        $this->assertEquals('this is a string test', StringHelper::truncateWords('this is a string test', 5));
-        $this->assertEquals('this is a string...', StringHelper::truncateWords('this is a string test', 4));
-        $this->assertEquals('this is a string!!!', StringHelper::truncateWords('this is a string test', 4, '!!!'));
-        $this->assertEquals('this is a big     space...', StringHelper::truncateWords('this is a big     space string', 5));
+        $this->assertEquals('это тестовая multibyte строка', StringHelper::truncateWords('это тестовая multibyte строка', 5));
+        $this->assertEquals('это тестовая multibyte...', StringHelper::truncateWords('это тестовая multibyte строка', 3));
+        $this->assertEquals('это тестовая multibyte!!!', StringHelper::truncateWords('это тестовая multibyte строка', 3, '!!!'));
+        $this->assertEquals('это строка с          неожиданными...', StringHelper::truncateWords('это строка с          неожиданными пробелами', 4));
     }
 }