diff --git a/core/modules/page_cache/page_cache.module b/core/modules/page_cache/page_cache.module
index cc26516a47..ee9f1640bd 100644
--- a/core/modules/page_cache/page_cache.module
+++ b/core/modules/page_cache/page_cache.module
@@ -5,7 +5,6 @@
  * Caches responses for anonymous users, request and response policies allowing.
  */
 
-use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
 
@@ -32,9 +31,8 @@ function page_cache_help($route_name, RouteMatchInterface $route_match) {
 }
 
 /**
- * Implements hook_form_FORM_ID_alter().
+ * Implements hook_form_FORM_ID_alter() for system_site_maintenance_mode.
  */
-function page_cache_form_system_site_maintenance_mode_alter(&$form, FormStateInterface $form_state, $form_id) {
-  $form['maintenance_mode_message']['#description'] = t('Since the page cache is enabled, you must flush the page cache to display your maintenance mode message to the site visitor. Visit the <a href=":performance-page-url" title="performance settings page">Performance Settings page</a> to flush the page cache.', [':performance-page-url' => Url::fromRoute('system.performance_settings')->toString()]);
+function page_cache_form_system_site_maintenance_mode_alter(&$form) {
+  $form['maintenance_mode_message']['#description'] = t('To display the maintenance mode message to all site visitors, flush the page cache on the <a href=":performance-page-url" title="performance settings page">Performance Settings page</a>.', [':performance-page-url' => Url::fromRoute('system.performance_settings')->toString()]);
 }
-