diff --git a/src/Symfony/Component/DependencyInjection/Compiler/CheckReferenceValidityPass.php b/src/Symfony/Component/DependencyInjection/Compiler/CheckReferenceValidityPass.php
index df0f55a830..80b81d695d 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/CheckReferenceValidityPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/CheckReferenceValidityPass.php
@@ -38,8 +38,6 @@ class CheckReferenceValidityPass implements CompilerPassInterface
     {
         $this->container = $container;
 
-        $ancestors = array();
-
         foreach ($container->getDefinitions() as $id => $definition) {
             if ($definition->isSynthetic() || $definition->isAbstract()) {
                 continue;