diff --git a/src/Symfony/Bridge/PhpUnit/Legacy/SymfonyTestsListenerTrait.php b/src/Symfony/Bridge/PhpUnit/Legacy/SymfonyTestsListenerTrait.php
index 77693421bacd..e260fb8dd685 100644
--- a/src/Symfony/Bridge/PhpUnit/Legacy/SymfonyTestsListenerTrait.php
+++ b/src/Symfony/Bridge/PhpUnit/Legacy/SymfonyTestsListenerTrait.php
@@ -49,7 +49,7 @@ public function __construct(array $mockedNamespaces = array())
             \PHPUnit_Util_Blacklist::$blacklistedClassNames[__CLASS__] = 2;
         } elseif (method_exists(Blacklist::class, 'addDirectory')) {
             (new BlackList())->getBlacklistedDirectories();
-            Blacklist::addDirectory(\dirname(\dirname((new \ReflectionClass(__CLASS__))->getFileName())));
+            Blacklist::addDirectory(\dirname((new \ReflectionClass(__CLASS__))->getFileName(), 2));
         } else {
             Blacklist::$blacklistedClassNames[__CLASS__] = 2;
         }