diff --git a/core/core.services.yml b/core/core.services.yml
index 3fbeb05..bc72d11 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -454,7 +454,7 @@ services:
     arguments: ['@html_fragment_renderer', '@html_page_renderer']
   html_fragment_renderer:
     class: Drupal\Core\Page\DefaultHtmlFragmentRenderer
-    arguments: ['@language_manager', '@module_handler', '@http_kernel', '@url_generator', '@?current_user']
+    arguments: ['@language_manager', '@module_handler', '@http_kernel', '@url_generator']
     calls:
       - [setRequest, ['@?request=']]
   html_fragment_renderer_no_blocks:
diff --git a/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php b/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
index e31a6a6..84a1539 100644
--- a/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
+++ b/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
@@ -37,13 +37,6 @@ class DefaultHtmlFragmentRenderer implements HtmlFragmentRendererInterface {
   protected $request;
 
   /**
-   * The current user.
-   *
-   * @var \Drupal\Core\Session\AccountInterface
-   */
-  protected $currentUser;
-
-  /**
    * The module handler.
    *
    * @var \Drupal\Core\Extension\ModuleHandlerInterface
@@ -82,15 +75,12 @@ class DefaultHtmlFragmentRenderer implements HtmlFragmentRendererInterface {
    *   The HTTP kernel.
    * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
    *   The URL generator.
-   * @param \Drupal\Core\Session\AccountInterface $current_user
-   *   The current user.
    */
-  public function __construct(LanguageManagerInterface $language_manager, ModuleHandlerInterface $module_handler, HttpKernel $http_kernel, UrlGeneratorInterface $url_generator, AccountInterface $current_user = NULL)  {
+  public function __construct(LanguageManagerInterface $language_manager, ModuleHandlerInterface $module_handler, HttpKernel $http_kernel, UrlGeneratorInterface $url_generator)  {
     $this->languageManager = $language_manager;
     $this->moduleHandler = $module_handler;
     $this->httpKernel = $http_kernel;
     $this->urlGenerator = $url_generator;
-    $this->currentUser = $current_user;
   }
 
   /**
@@ -103,29 +93,6 @@ public function setRequest(Request $request) {
     $this->request = $request;
   }
 
-  /**
-   * Determines whether blocks are cacheable.
-   *
-   * @return bool
-   *   Returns TRUE if blocks are cacheable, otherwise FALSE.
-   */
-  protected function isBlockCachingEnabled() {
-    if (!isset($this->blockCachingEnabled)) {
-      // Block caching is not compatible with node_access modules. We also
-      // preserve the submission of forms in blocks, by fetching from cache
-      // only if the request method is 'GET' (or 'HEAD'). User 1 being out of
-      // the regular 'roles define permissions' schema, it brings too many
-      // chances of having unwanted output get in the cache and later be served
-      // to other users. We therefore exclude user 1 from block caching.
-      if (!$this->request) {
-        $this->blockCachingEnabled = FALSE;
-      }
-      else {
-        $this->blockCachingEnabled = $this->currentUser->id() !== 1 && count($this->moduleHandler->getImplementations('node_grants')) == 0 && $this->request->isMethodSafe();
-      }
-    }
-    return $this->blockCachingEnabled;
-  }
 
   /**
    * Gathers all blocks to be added to the page array.
@@ -270,10 +237,12 @@ protected function getBlocksByRegion($region) {
           $controller = 'Drupal\block\DefaultBlockController::respond';
           $attributes = $this->request->attributes->all();
           $attributes['block'] = $block;
-          $attributes['caching'] = $this->isBlockCachingEnabled();
 
-          $response = $this->httpKernel->forward($controller, $attributes);
-          $fragment = $response->getHtmlFragment();
+          $response = $this->httpKernel->forward($controller, $attributes, $this->request->query->all());
+          // Ensure that the subrequest returned what we expected.
+          if ($response->isOk() && $response instanceof HtmlFragmentResponse) {
+            $fragment = $response->getHtmlFragment();
+          }
         }
         catch (\Exception $e) {
           $fragment = NULL;
diff --git a/core/lib/Drupal/Core/Page/HtmlFragmentResponse.php b/core/lib/Drupal/Core/Page/HtmlFragmentResponse.php
index 7310e3d..53b0aa5 100644
--- a/core/lib/Drupal/Core/Page/HtmlFragmentResponse.php
+++ b/core/lib/Drupal/Core/Page/HtmlFragmentResponse.php
@@ -37,4 +37,4 @@ public function getHtmlFragment() {
     return $this->htmlFragment;
   }
 
-} 
+}
diff --git a/core/modules/block/block.routing.yml b/core/modules/block/block.routing.yml
index 8196bd2..2d98606 100644
--- a/core/modules/block/block.routing.yml
+++ b/core/modules/block/block.routing.yml
@@ -56,9 +56,8 @@ block.category_autocomplete:
     _permission: 'administer blocks'
 
 block.view:
-  path: '/block-view/{block}/{caching}'
+  path: '/block-view/{block}'
   defaults:
     _controller: 'block_controller:respond'
-    caching: false
   requirements:
     _entity_access: 'block.view'
diff --git a/core/modules/block/lib/Drupal/block/DefaultBlockController.php b/core/modules/block/lib/Drupal/block/DefaultBlockController.php
index bbae480..9db7d0d 100644
--- a/core/modules/block/lib/Drupal/block/DefaultBlockController.php
+++ b/core/modules/block/lib/Drupal/block/DefaultBlockController.php
@@ -5,11 +5,88 @@
  */
 
 namespace Drupal\block;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Session\AccountInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
 
 /**
  * Default controller for rendering a block.
  */
-class DefaultBlockController {
+class DefaultBlockController implements ContainerInjectionInterface {
+
+  /**
+   * The current request.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
+   */
+  protected $request;
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $currentUser;
+
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * Constructs a new DefaultBlockController.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   * @param \Drupal\Core\Session\AccountInterface $current_user
+   *   The current user.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler.
+   */
+  public function __construct(Request $request, AccountInterface $current_user, ModuleHandlerInterface $module_handler) {
+    $this->request = $request;
+    $this->currentUser = $current_user;
+    $this->moduleHandler = $module_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('request'),
+      $container->get('current_user'),
+      $container->get('module_handler')
+    );
+  }
+
+  /**
+   * Determines whether blocks are cacheable.
+   *
+   * @return bool
+   *   Returns TRUE if blocks are cacheable, otherwise FALSE.
+   */
+  protected function isBlockCachingEnabled() {
+    if (!isset($this->blockCachingEnabled)) {
+      // Block caching is not compatible with node_access modules. We also
+      // preserve the submission of forms in blocks, by fetching from cache
+      // only if the request method is 'GET' (or 'HEAD'). User 1 being out of
+      // the regular 'roles define permissions' schema, it brings too many
+      // chances of having unwanted output get in the cache and later be served
+      // to other users. We therefore exclude user 1 from block caching.
+      if (!$this->request) {
+        $this->blockCachingEnabled = FALSE;
+      }
+      else {
+        $this->blockCachingEnabled = $this->currentUser->id() !== 1 && count($this->moduleHandler->getImplementations('node_grants')) == 0 && $this->request->isMethodSafe();
+      }
+    }
+    return $this->blockCachingEnabled;
+  }
 
   /**
    * Renders a provided block into an HtmlFragment.
@@ -17,13 +94,10 @@ class DefaultBlockController {
    * @param \Drupal\block\BlockInterface $block
    *   The block to render.
    *
-   * @param bool $caching
-   *   Is caching enabled.
-   *
    * @return \Drupal\Core\Page\HtmlFragment
    */
-  public function respond(BlockInterface $block, $caching) {
-    return $block->getHtmlFragment($caching);
+  public function respond(BlockInterface $block) {
+    return $block->getHtmlFragment($this->isBlockCachingEnabled());
   }
 
 }