diff --git a/typo3/sysext/extbase/Classes/Validation/Validator/StringLengthValidator.php b/typo3/sysext/extbase/Classes/Validation/Validator/StringLengthValidator.php
index c249773a633eaebfc888ee83cfbcacbca2e00675..68fd428f98095b5987a2012abea14caf760f44ee 100644
--- a/typo3/sysext/extbase/Classes/Validation/Validator/StringLengthValidator.php
+++ b/typo3/sysext/extbase/Classes/Validation/Validator/StringLengthValidator.php
@@ -55,8 +55,7 @@ class StringLengthValidator extends AbstractValidator
             return;
         }
 
-        // @todo Use \TYPO3\CMS\Core\Charset\CharsetConverter::strlen() instead; How do we get the charset?
-        $stringLength = strlen($value);
+        $stringLength = mb_strlen($value, 'utf-8');
         $isValid = true;
         if ($stringLength < $this->options['minimum']) {
             $isValid = false;
diff --git a/typo3/sysext/extbase/Tests/Unit/Validation/Validator/StringLengthValidatorTest.php b/typo3/sysext/extbase/Tests/Unit/Validation/Validator/StringLengthValidatorTest.php
index fcb7368ba5b95a90443980e4f0e79463122d06e8..30cb907f86a2189e5f83aab8b6d70fb8cbd5ba3e 100644
--- a/typo3/sysext/extbase/Tests/Unit/Validation/Validator/StringLengthValidatorTest.php
+++ b/typo3/sysext/extbase/Tests/Unit/Validation/Validator/StringLengthValidatorTest.php
@@ -268,8 +268,11 @@ class StringLengthValidatorTest extends \TYPO3\Components\TestingFramework\Core\
      */
     public function validateRegardsMultibyteStringsCorrectly()
     {
-        //		$this->validatorOptions(array('maximum' => 8));
-//		$this->assertFalse($this->validator->validate('überlang')->hasErrors());
-        $this->markTestSkipped('Validator needs to be adjusted regarding multibyte char lengths.');
+        $options = ['minimum' => 0, 'maximum' => 8];
+        $validator = $this->getMockBuilder($this->validatorClassName)
+            ->setMethods(['dummy'])
+            ->setConstructorArgs([$options])
+            ->getMock();
+        $this->assertFalse($validator->validate('überlang')->hasErrors());
     }
 }