diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index a6c31e8a3f821..8c70005d28577 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -584,6 +584,11 @@ protected function initializeContainer()
                     file_put_contents($this->getCacheDir().'/'.$class.'Compiler.log', null !== $container ? implode("\n", $container->getCompiler()->getLog()) : '');
                 }
             }
+
+            if ($oldContainer = file_exists($cache->getPath()) ? @include $cache->getPath() : false) {
+                $oldContainer = new \ReflectionClass($oldContainer);
+            }
+
             $this->dumpContainer($cache, $container, $class, $this->getContainerBaseClass());
 
             $fresh = false;
@@ -592,7 +597,15 @@ protected function initializeContainer()
         $this->container = require $cache->getPath();
         $this->container->set('kernel', $this);
 
-        if (!$fresh && $this->container->has('cache_warmer')) {
+        if ($fresh) {
+            return;
+        }
+
+        if ($oldContainer && get_class($this->container) !== $oldContainer->name) {
+            (new Filesystem())->remove(dirname($oldContainer->getFileName()));
+        }
+
+        if ($this->container->has('cache_warmer')) {
             $this->container->get('cache_warmer')->warmUp($this->container->getParameter('kernel.cache_dir'));
         }
     }
@@ -773,6 +786,9 @@ protected function dumpContainer(ConfigCache $cache, ContainerBuilder $container
             @chmod($dir.$file, 0666 & ~umask());
         }
 
+        // track changes made to the container directory
+        $container->fileExists(dirname($dir.$file));
+
         $cache->write($rootCode, $container->getResources());
     }
 
diff --git a/src/Symfony/Component/HttpKernel/Tests/KernelTest.php b/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
index 052e5766d6c7c..4392e30e652f3 100644
--- a/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
@@ -771,13 +771,38 @@ public function testSymfonyEnvironmentVariables()
 
     public function testProjectDirExtension()
     {
-        $kernel = new CustomProjectDirKernel('test', true);
+        $kernel = new CustomProjectDirKernel();
         $kernel->boot();
 
         $this->assertSame('foo', $kernel->getProjectDir());
         $this->assertSame('foo', $kernel->getContainer()->getParameter('kernel.project_dir'));
     }
 
+    public function testKernelReset()
+    {
+        (new Filesystem())->remove(__DIR__.'/Fixtures/cache');
+
+        $kernel = new CustomProjectDirKernel();
+        $kernel->boot();
+
+        $containerClass = get_class($kernel->getContainer());
+        $containerFile = (new \ReflectionClass($kernel->getContainer()))->getFileName();
+        unlink(__DIR__.'/Fixtures/cache/custom/FixturesCustomDebugProjectContainer.php.meta');
+
+        $kernel = new CustomProjectDirKernel();
+        $kernel->boot();
+
+        $this->assertSame($containerClass, get_class($kernel->getContainer()));
+        $this->assertFileExists($containerFile);
+        unlink(__DIR__.'/Fixtures/cache/custom/FixturesCustomDebugProjectContainer.php.meta');
+
+        $kernel = new CustomProjectDirKernel(function ($container) { $container->register('foo', 'stdClass'); });
+        $kernel->boot();
+
+        $this->assertTrue(get_class($kernel->getContainer()) !== $containerClass);
+        $this->assertFileNotExists($containerFile);
+    }
+
     /**
      * Returns a mock for the BundleInterface.
      *
@@ -878,12 +903,14 @@ public function handle(Request $request, $type = self::MASTER_REQUEST, $catch =
 class CustomProjectDirKernel extends Kernel
 {
     private $baseDir;
+    private $buildContainer;
 
-    public function __construct()
+    public function __construct(\Closure $buildContainer = null)
     {
-        parent::__construct('test', false);
+        parent::__construct('custom', true);
 
         $this->baseDir = 'foo';
+        $this->buildContainer = $buildContainer;
     }
 
     public function registerBundles()
@@ -904,4 +931,11 @@ public function getRootDir()
     {
         return __DIR__.'/Fixtures';
     }
+
+    protected function build(ContainerBuilder $container)
+    {
+        if ($build = $this->buildContainer) {
+            $build($container);
+        }
+    }
 }