diff --git a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
index c21c28550c..ac3a7f96d0 100644
--- a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
+++ b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
@@ -83,6 +83,11 @@ class Deprecation
                     $this->triggeringFile = isset($trace[1 + $j]['args'][1]) ? realpath($trace[1 + $j]['args'][1]) : (new \ReflectionClass($class))->getFileName();
                     $this->getOriginalFilesStack();
                     array_splice($this->originalFilesStack, 0, $j, [$this->triggeringFile]);
+
+                    if (preg_match('/(?|"([^"]++)" that is deprecated|should implement method "([^:]++))/', $message, $m) || preg_match('/^(?:The|Method) "([^":]++)/', $message, $m)) {
+                        $this->triggeringFile = (new \ReflectionClass($m[1]))->getFileName();
+                        array_unshift($this->originalFilesStack, $this->triggeringFile);
+                    }
                 }
 
                 break;
diff --git a/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/debug_class_loader_deprecation.phpt b/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/debug_class_loader_deprecation.phpt
new file mode 100644
index 0000000000..a6b0133af9
--- /dev/null
+++ b/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/debug_class_loader_deprecation.phpt
@@ -0,0 +1,41 @@
+--TEST--
+Test that a deprecation from the DebugClassLoader triggered by an app class extending a vendor one is considered direct.
+--FILE--
+<?php
+
+$k = 'SYMFONY_DEPRECATIONS_HELPER';
+putenv($k.'='.$_SERVER[$k] = $_ENV[$k] = 'max[total]=0');
+putenv('ANSICON');
+putenv('ConEmuANSI');
+putenv('TERM');
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = dirname($vendor);
+}
+define('PHPUNIT_COMPOSER_INSTALL', $vendor.'/vendor/autoload.php');
+require PHPUNIT_COMPOSER_INSTALL;
+require_once __DIR__.'/../../bootstrap.php';
+eval(<<<'EOPHP'
+namespace PHPUnit\Util;
+
+class Test
+{
+    public static function getGroups()
+    {
+        return array();
+    }
+}
+EOPHP
+);
+require __DIR__.'/fake_vendor/autoload.php';
+
+\Symfony\Component\ErrorHandler\DebugClassLoader::enable();
+new \App\Services\ExtendsDeprecatedFromVendor();
+
+?>
+--EXPECTF--
+Remaining direct deprecation notices (1)
+
+  1x: The "App\Services\ExtendsDeprecatedFromVendor" class extends "fcy\lib\DeprecatedClass" that is deprecated.
+    1x in DebugClassLoader::loadClass from Symfony\Component\ErrorHandler
diff --git a/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/fake_app/ExtendsDeprecatedFromVendor.php b/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/fake_app/ExtendsDeprecatedFromVendor.php
new file mode 100644
index 0000000000..b4305e0d08
--- /dev/null
+++ b/src/Symfony/Bridge/PhpUnit/Tests/DeprecationErrorHandler/fake_app/ExtendsDeprecatedFromVendor.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace App\Services;
+
+use fcy\lib\DeprecatedClass;
+
+final class ExtendsDeprecatedFromVendor extends DeprecatedClass
+{
+}
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/Functional/app/CachePools/bundles.php b/src/Symfony/Bundle/FrameworkBundle/Tests/Functional/app/CachePools/bundles.php
index 15ff182c6f..2e46e896bc 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/Functional/app/CachePools/bundles.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/Functional/app/CachePools/bundles.php
@@ -14,5 +14,4 @@ use Symfony\Bundle\FrameworkBundle\Tests\Functional\Bundle\TestBundle\TestBundle
 
 return [
     new FrameworkBundle(),
-    new TestBundle(),
 ];
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index 6f35643eb3..f36f4bed4a 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -466,7 +466,7 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
                 if (!flock($lock, $wouldBlock ? \LOCK_SH : \LOCK_EX)) {
                     fclose($lock);
                     $lock = null;
-                } elseif (!\is_object($this->container = include $cachePath)) {
+                } elseif (!is_file($cachePath) || !\is_object($this->container = include $cachePath)) {
                     $this->container = null;
                 } elseif (!$oldContainer || \get_class($this->container) !== $oldContainer->name) {
                     flock($lock, \LOCK_UN);