--- /dev/null
+--TEST--
+Test DebugClassLoader with previously loaded parents
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+use Symfony\Component\Debug\DebugClassLoader;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+ $vendor = dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+class_exists(FinalMethod::class);
+
+set_error_handler(function ($type, $msg) { echo $msg, "\n"; });
+
+DebugClassLoader::enable();
+
+class_exists(ExtendedFinalMethod::class);
+
+?>
+--EXPECTF--
+The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod()" method is considered final since version 3.3. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".