diff --git a/src/Symfony/Component/Validator/Tests/ConstraintViolationTest.php b/src/Symfony/Component/Validator/Tests/ConstraintViolationTest.php
index 8e0869824f50..eb5810dafbd8 100644
--- a/src/Symfony/Component/Validator/Tests/ConstraintViolationTest.php
+++ b/src/Symfony/Component/Validator/Tests/ConstraintViolationTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Validator\ConstraintViolation;
 use Symfony\Component\Validator\Tests\Fixtures\CustomArrayObject;
+use Symfony\Component\Validator\Tests\Fixtures\ToString;
 
 class ConstraintViolationTest extends TestCase
 {