diff --git a/core/lib/Drupal/Core/Page/RenderHtmlRenderer.php b/core/lib/Drupal/Core/Page/RenderHtmlRenderer.php
index 9358e25..6954f06 100644
--- a/core/lib/Drupal/Core/Page/RenderHtmlRenderer.php
+++ b/core/lib/Drupal/Core/Page/RenderHtmlRenderer.php
@@ -52,11 +52,8 @@ public function render(array $render_array) {
 
     $attached = isset($render_array['#attached']) ? $render_array['#attached'] : [];
     $attached += [
-      '_drupal_add_feed' => [],
       'feed' => [],
-      '_drupal_add_html_head' => [],
       'html_head' => [],
-      '_drupal_add_html_head_link' => [],
       'html_head_link' => [],
     ];
 
@@ -65,14 +62,8 @@ public function render(array $render_array) {
     foreach ($attached['feed'] as $feed) {
       $fragment->addLinkElement(new FeedLinkElement($feed[1], $this->urlGenerator->generateFromPath($feed[0])));
     }
-    foreach ($attached['_drupal_add_feed'] as $feed) {
-      $fragment->addLinkElement(new FeedLinkElement($feed[1], $this->urlGenerator->generateFromPath($feed[0])));
-    }
 
     // Add generic links from the page content.
-    foreach ($attached['_drupal_add_html_head_link'] as $link) {
-      $fragment->addLinkElement(new LinkElement($this->urlGenerator->generateFromPath($link[0]['href']), $link[0]['rel']));
-    }
     foreach ($attached['html_head_link'] as $link) {
       $fragment->addLinkElement(new LinkElement($this->urlGenerator->generateFromPath($link[0]['href']), $link[0]['rel']));
     }