diff --git a/core/lib/Drupal/Core/Routing/CompiledRoute.php b/core/lib/Drupal/Core/Routing/CompiledRoute.php
index 7354e12..5fb1b4a 100644
--- a/core/lib/Drupal/Core/Routing/CompiledRoute.php
+++ b/core/lib/Drupal/Core/Routing/CompiledRoute.php
@@ -177,7 +177,19 @@ public function getRequirements() {
    * {@inheritdoc}
    */
   public function serialize() {
-    $data = unserialize(parent::serialize());
+    $data = [];
+    // All symfony provided variables.
+    // @todo A lot of them are actually not used by Drupal, at least for now,
+    //   so think about optimize them out.
+    $data['vars'] = $this->getVariables();
+    $data['path_prefix'] = $this->getStaticPrefix();
+    $data['path_regex'] = $this->getRegex();
+    $data['path_tokens'] = $this->getTokens();
+    $data['path_vars'] = $this->getPathVariables();
+    $data['host_regex'] = $this->getHostRegex();
+    $data['host_tokens'] = $this->getHostTokens();
+    $data['host_vars'] = $this->getHostVariables();
+
     $data['fit'] = $this->fit;
     $data['patternOutline'] = $this->patternOutline;
     $data['numParts'] = $this->numParts;
@@ -188,9 +200,9 @@ public function serialize() {
   /**
    * {@inheritdoc}
    */
-  public function unserialize($serialized)
-  {
+  public function unserialize($serialized) {
     parent::unserialize($serialized);
+
     $data = unserialize($serialized);
 
     $this->fit = $data['fit'];
diff --git a/core/lib/Drupal/Core/Routing/RoutePreloader.php b/core/lib/Drupal/Core/Routing/RoutePreloader.php
index 7952d17..c45bee6 100644
--- a/core/lib/Drupal/Core/Routing/RoutePreloader.php
+++ b/core/lib/Drupal/Core/Routing/RoutePreloader.php
@@ -85,7 +85,7 @@ public function onRequest(KernelEvent $event) {
    */
   protected function loadNonAdminRoutes() {
     if ($routes = $this->state->get('routing.non_admin_routes', array())) {
-      $this->routeProvider->getRoutesByNames($routes);
+      $this->routeProvider->getRoutesByNames($routes, FALSE);
     }
   }
 
diff --git a/core/lib/Drupal/Core/Routing/RouteProvider.php b/core/lib/Drupal/Core/Routing/RouteProvider.php
index da9dc1b..58597c1 100644
--- a/core/lib/Drupal/Core/Routing/RouteProvider.php
+++ b/core/lib/Drupal/Core/Routing/RouteProvider.php
@@ -153,22 +153,9 @@ public function getRouteByName($name) {
   }
 
   /**
-   * Find many routes by their names using the provided list of names.
-   *
-   * Note that this method may not throw an exception if some of the routes
-   * are not found. It will just return the list of those routes it found.
-   *
-   * This method exists in order to allow performance optimizations. The
-   * simple implementation could be to just repeatedly call
-   * $this->getRouteByName().
-   *
-   * @param array $names
-   *   The list of names to retrieve.
-   *
-   * @return \Symfony\Component\Routing\Route[]
-   *   Iterable thing with the keys the names of the $names argument.
+   * {@inheritdoc}
    */
-  public function getRoutesByNames($names) {
+  public function getRoutesByNames($names, $unserialize = TRUE) {
 
     if (empty($names)) {
       throw new \InvalidArgumentException('You must specify the route names to load');
@@ -181,11 +168,17 @@ public function getRoutesByNames($names) {
       $result = $this->connection->query('SELECT name, route FROM {' . $this->connection->escapeTable($this->tableName) . '} WHERE name IN (:names)', array(':names' => $routes_to_load));
       $routes = $result->fetchAllKeyed();
 
-      foreach ($routes as $name => $route) {
-        $this->routes[$name] = unserialize($route);
-      }
+      $this->routes += $routes;
     }
 
+    if ($unserialize) {
+      foreach ($names as $name) {
+        // The specified route name might not exist.
+        if (isset($this->routes[$name])) {
+          $this->routes[$name] = is_string($this->routes[$name]) ? unserialize($this->routes[$name]) : $this->routes[$name];
+        }
+      }
+    }
     return array_intersect_key($this->routes, array_flip($names));
   }
 
diff --git a/core/lib/Drupal/Core/Routing/RouteProviderInterface.php b/core/lib/Drupal/Core/Routing/RouteProviderInterface.php
index 8c8e356..d4450b5 100644
--- a/core/lib/Drupal/Core/Routing/RouteProviderInterface.php
+++ b/core/lib/Drupal/Core/Routing/RouteProviderInterface.php
@@ -18,6 +18,27 @@
 interface RouteProviderInterface extends RouteProviderBaseInterface {
 
   /**
+   * Find many routes by their names using the provided list of names.
+   *
+   * Note that this method may not throw an exception if some of the routes
+   * are not found. It will just return the list of those routes it found.
+   *
+   * This method exists in order to allow performance optimizations. The
+   * simple implementation could be to just repeatedly call
+   * $this->getRouteByName().
+   *
+   * @param array $names
+   *   The list of names to retrieve.
+   *
+   * @param bool $unserialize
+   *   (optional) Determines whether the routes should be unserialized.
+   *
+   * @return string[]\Symfony\Component\Routing\Route[]
+   *   Iterable thing with the keys the names of the $names argument.
+   */
+  public function getRoutesByNames($names, $unserialize = TRUE);
+
+  /**
    * Get all routes which match a certain pattern.
    *
    * @param string $pattern
diff --git a/core/modules/system/src/Tests/Routing/MockRouteProvider.php b/core/modules/system/src/Tests/Routing/MockRouteProvider.php
index dce1b27..0bd8b66 100644
--- a/core/modules/system/src/Tests/Routing/MockRouteProvider.php
+++ b/core/modules/system/src/Tests/Routing/MockRouteProvider.php
@@ -59,7 +59,7 @@ public function getRouteByName($name) {
   /**
    * Implements \Symfony\Cmf\Component\Routing\RouteProviderInterface::getRoutesByName().
    */
-  public function getRoutesByNames($names) {
+  public function getRoutesByNames($names, $unserialize = TRUE) {
     $routes = array();
     foreach ($names as $name) {
       $routes[] = $this->routes->get($name);
diff --git a/core/tests/Drupal/Tests/Core/Routing/RoutePreloaderTest.php b/core/tests/Drupal/Tests/Core/Routing/RoutePreloaderTest.php
index 109a3f2..9077ee7 100644
--- a/core/tests/Drupal/Tests/Core/Routing/RoutePreloaderTest.php
+++ b/core/tests/Drupal/Tests/Core/Routing/RoutePreloaderTest.php
@@ -168,7 +168,7 @@ public function testOnRequestOnHtml() {
 
     $this->routeProvider->expects($this->once())
       ->method('getRoutesByNames')
-      ->with(array('test2'));
+      ->with(['test2'], FALSE);
     $this->state->expects($this->once())
       ->method('get')
       ->with('routing.non_admin_routes')