core/core.services.yml                             |  3 ++-
 .../Core/Cache/MenuActiveTrailCacheContext.php     | 28 +++++++---------------
 2 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/core/core.services.yml b/core/core.services.yml
index 13fc8d5..7ac81da 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -35,7 +35,8 @@ services:
       - { name: cache.context}
   cache_context.menu.active_trail:
     class: Drupal\Core\Cache\MenuActiveTrailCacheContext
-    arguments: ['@menu.active_trail']
+    calls:
+      - [setContainer, ['@service_container']]
     tags:
       - { name: cache.context}
   cache_tags.invalidator:
diff --git a/core/lib/Drupal/Core/Cache/MenuActiveTrailCacheContext.php b/core/lib/Drupal/Core/Cache/MenuActiveTrailCacheContext.php
index 755b885..3ba4ad2 100644
--- a/core/lib/Drupal/Core/Cache/MenuActiveTrailCacheContext.php
+++ b/core/lib/Drupal/Core/Cache/MenuActiveTrailCacheContext.php
@@ -7,29 +7,15 @@
 
 namespace Drupal\Core\Cache;
 
-use Drupal\Core\Menu\MenuActiveTrailInterface;
+use Symfony\Component\DependencyInjection\ContainerAware;
 
 /**
  * Defines the MenuActiveTrailCacheContext service.
+ *
+ * This class is container-aware to avoid initializing the 'menu.active_trail'
+ * service (and its dependencies) when it is not necessary.
  */
-class MenuActiveTrailCacheContext implements CalculatedCacheContextInterface {
-
-  /**
-   * The active menu trail service.
-   *
-   * @var \Drupal\Core\Menu\MenuActiveTrailInterface
-   */
-  protected $menuActiveTrail;
-
-  /**
-   * Constructs a new MenuActiveTrailCacheContext service.
-   *
-   * @param \Drupal\Core\Menu\MenuActiveTrailInterface $menu_active_trail
-   *   The active menu trail service.
-   */
-  public function __construct(MenuActiveTrailInterface $menu_active_trail) {
-    $this->menuActiveTrail = $menu_active_trail;
-  }
+class MenuActiveTrailCacheContext extends ContainerAware implements CalculatedCacheContextInterface {
 
   /**
    * {@inheritdoc}
@@ -42,7 +28,9 @@ public static function getLabel() {
    * {@inheritdoc}
    */
   public function getContext($menu_name) {
-    return 'menu_trail.' . implode('|', $this->menuActiveTrail->getActiveTrailIds($menu_name));
+    $active_trail = $this->container->get('menu.active_trail')
+      ->getActiveTrailIds($menu_name);
+    return 'menu_trail.' . implode('|', $active_trail);
   }
 
 }