Symfony 2.8: ResourceInterface :: isFresh () устарела с версии 2.8

После обновления до Symfony до 2.8 я обнаружил множество предупреждений об устаревании:

Класс «Symfony \ Bundle \ AsseticBundle \ Config \ AsseticResource» является
выполнение проверки ресурса через ResourceInterface :: isFresh (),
который устарел с 2.8 и будет удален в 3.0 (54 раза)

Стек (из профайлера Symfony)

BCResourceInterfaceChecker::isFresh() (called from bootstrap.php.cache at line 3061)
ResourceCheckerConfigCache::isFresh() (called from ResourceCheckerConfigCacheFactory.php at line 45)
ResourceCheckerConfigCacheFactory::cache() (called from classes.php at line 1328)
Router::getMatcher() (called from classes.php at line 1288)
Router::match() (called from classes.php at line 7170)
Router::match() (called from classes.php at line 2086)
RouterListener::onKernelRequest()
call_user_func() (called from WrappedListener.php at line 61)
WrappedListener::__invoke()
call_user_func() (called from classes.php at line 1853)
EventDispatcher::doDispatch() (called from classes.php at line 1771)
EventDispatcher::dispatch() (called from TraceableEventDispatcher.php at line 132)
TraceableEventDispatcher::dispatch() (called from bootstrap.php.cache at line 3178)
HttpKernel::handleRaw() (called from bootstrap.php.cache at line 3151)
HttpKernel::handle() (called from bootstrap.php.cache at line 3302)
ContainerAwareHttpKernel::handle() (called from bootstrap.php.cache at line 2498)
Kernel::handle() (called from app_dev.php at line 29)

для апгрейда я использовал:

composer.phar update symfony/symfony --with-dependencies

это мой композитор.json

{
"name": "framework/symfony",
"license": "proprietary",
"type": "project",
"autoload": {
"psr-4": {
"": "src/"}
},
"require": {
"php": ">=5.3.9",
"symfony/symfony": "2.8.*",
"doctrine/orm": "^2.4.8",
"doctrine/doctrine-bundle": "~1.4",
"symfony/assetic-bundle": "~2.3",
"symfony/swiftmailer-bundle": "~2.3",
"symfony/monolog-bundle": "~2.4",
"sensio/distribution-bundle": "~4.0",
"sensio/framework-extra-bundle": "^3.0.2",
"incenteev/composer-parameter-handler": "~2.0"},
"require-dev": {
"sensio/generator-bundle": "~2.3"},
"scripts": {
"post-install-cmd": [
"Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget"],
"post-update-cmd": [
"Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile",
"Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget"]
},
"config": {
"bin-dir": "bin"},
"extra": {
"symfony-app-dir": "app",
"symfony-web-dir": "web",
"symfony-assets-install": "relative",
"incenteev-parameters": {
"file": "app/config/parameters.yml"}
}
}

как решить это предупреждение об устаревании?