diff --git a/core/modules/page_cache/page_cache.module b/core/modules/page_cache/page_cache.module
index ff7286199d..2879b08e0c 100644
--- a/core/modules/page_cache/page_cache.module
+++ b/core/modules/page_cache/page_cache.module
@@ -23,7 +23,7 @@ function page_cache_help($route_name, RouteMatchInterface $route_match) {
       $output .= '<dd>' . t('Pages are usually identical for all anonymous users, while they can be personalized for each authenticated user. This is why entire pages can be cached for anonymous users, whereas they will have to be rebuilt for every authenticated user.') . '</dd>';
       $output .= '<dd>' . t('To speed up your site for authenticated users, see the <a href=":dynamic_page_cache-help">Dynamic Page Cache module</a>.', [':dynamic_page_cache-help' => (\Drupal::moduleHandler()->moduleExists('dynamic_page_cache')) ? Url::fromRoute('help.page', ['name' => 'dynamic_page_cache'])->toString() : '#']) . '</p>';
       $output .= '<dt>' . t('Configuring the internal page cache') . '</dt>';
-      $output .= '<dd>' . t('On the <a href=":cache-settings">Performance page</a>, you can configure how long browsers and proxies may cache pages; that setting is also respected by the Internal Page Cache module. There is no other configuration.', [':cache-settings' => \Drupal::url('system.performance_settings')]) . '</dd>';
+      $output .= '<dd>' . t('On the <a href=":cache-settings">Performance page</a>, you can configure how long browsers and proxies may cache pages based on the Cache-Control header; this setting is ignored by the Internal Page Cache module, which caches pages permanently until invalidation, unless they carry an Expires header. There is no other configuration.', [':cache-settings' => \Drupal::url('system.performance_settings')]) . '</dd>';
       $output .= '</dl>';
 
       return $output;