core/lib/Drupal/Core/Controller/HtmlController.php | 28 ++++++++++------------
 .../Drupal/Core/Render/BareHtmlPageRenderer.php    |  4 ++--
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/core/lib/Drupal/Core/Controller/HtmlController.php b/core/lib/Drupal/Core/Controller/HtmlController.php
index 27f3bb9..5171635 100644
--- a/core/lib/Drupal/Core/Controller/HtmlController.php
+++ b/core/lib/Drupal/Core/Controller/HtmlController.php
@@ -167,26 +167,22 @@ public function renderMainContent(array $page, $title, array $custom) {
     // page.html.twig, hence add them here, just before rendering html.html.twig.
     static::buildPageTopAndBottom($html);
 
-    // The three parts of rendered markup on a page (page_top, page and
-    // page_bottom) must be rendered with $is_root_call = TRUE, so that their
-    // #post_render_cache callbacks have been executed and their #attached
-    // assets have been bubbled.
-    // html.html.twig, we must not perform #post_render_cache callbacks anymore,
-    // because we must be able to generate the list of all the assets for the
-    // rendered page.
-    drupal_render($html['page'], TRUE);
+    // The three parts of rendered markup in html.html.twig (page_top, page and
+    // page_bottom) must be rendered with drupal_render_root(), so that their
+    // #post_render_cache callbacks are executed (which may attach additional
+    // assets).
+    // html.html.twig must be able to render the final list of attached assets,
+    // and hence may not execute any #post_render_cache_callbacks (because they
+    // might add yet more assets to be attached), and therefore it must be
+    // rendered with drupal_render(), not drupal_render_root().
+    drupal_render_root($html['page']);
     if (isset($html['page_top'])) {
-      drupal_render($html['page_top'], TRUE);
+      drupal_render_root($html['page_top']);
     }
     if (isset($html['page_bottom'])) {
-      drupal_render($html['page_bottom'], TRUE);
+      drupal_render_root($html['page_bottom']);
     }
-
-    // The three parts of rendered markup on a page (page_top, page and
-    // page_bottom) have already been rendered. Rendering the html.html.twig
-    // template may only do "simple" rendering, without any bubbling, because we
-    // must be able to generate the list of all the assets for the rendered page.
-    $content = drupal_render($html, FALSE);
+    $content = drupal_render_root($html);
 
     // Store the cache tags associated with this page in a X-Drupal-Cache-Tags
     // header. Also associate the "rendered" cache tag. This allows us to
diff --git a/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php b/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
index 19fece6..5ec957e 100644
--- a/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
+++ b/core/lib/Drupal/Core/Render/BareHtmlPageRenderer.php
@@ -71,8 +71,8 @@ protected function renderBarePage(array $content, $title, array $page_additions,
 
     // We must first render the contents of the html.html.twig template, see
     // \Drupal\Core\Controller\HtmlController::renderPage() for details.
-    drupal_render($html['page'], TRUE);
-    return drupal_render($html, FALSE);
+    drupal_render_root($html['page']);
+    return drupal_render($html);
   }
 
 }