core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php | 2 +-
 core/lib/Drupal/Core/Page/DefaultHtmlPageRenderer.php     | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php b/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
index 0cdd613..d2ccc88 100644
--- a/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
+++ b/core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php
@@ -49,7 +49,7 @@ public function render(HtmlFragmentInterface $fragment, $status_code = 200) {
     }
 
     // Build the full page array by calling drupal_prepare_page(), which invokes
-    // hook_page_build(). This adds the other regions to the page.
+    // _block_page_build(). This adds the other regions to the page.
     $page_array = drupal_prepare_page($page_content);
 
     // Build the HtmlPage object.
diff --git a/core/lib/Drupal/Core/Page/DefaultHtmlPageRenderer.php b/core/lib/Drupal/Core/Page/DefaultHtmlPageRenderer.php
index eea3e16..2968deb 100644
--- a/core/lib/Drupal/Core/Page/DefaultHtmlPageRenderer.php
+++ b/core/lib/Drupal/Core/Page/DefaultHtmlPageRenderer.php
@@ -45,7 +45,7 @@ public function render(HtmlPage $page) {
    * This is functionally very similar to DefaultHtmlFragmentRenderer::render()
    * but with the following important differences:
    *
-   * - drupal_prepare_page() and hook_page_build() cannot be invoked on the
+   * - drupal_prepare_page() and _block_page_build() cannot be invoked on the
    *   maintenance and install pages, since possibly enabled page layout/block
    *   modules would replace the main page content with configured region
    *   content.
@@ -93,9 +93,9 @@ public static function renderPage($main, $title = '', $theme = 'maintenance', ar
     // Add default properties.
     $page_array += element_info('page');
 
-    // hook_page_build() cannot be invoked on the maintenance and install pages,
-    // because the application is in an unknown or special state.
-    // In particular on the install page, invoking hook_page_build() directly
+    // _block_page_build() cannot be invoked on the maintenance and install
+    // pages, because the application is in an unknown or special state.
+    // In particular on the install page, invoking _block_page_build() directly
     // after e.g. Block module has been installed would *replace* the installer
     // output with the configured blocks of the installer theme (loaded from
     // default configuration of the installation profile).