diff --git a/core/themes/seven/js/responsive-details.js b/core/themes/seven/js/responsive-details.js
index 6d1787b..a98aede 100644
--- a/core/themes/seven/js/responsive-details.js
+++ b/core/themes/seven/js/responsive-details.js
@@ -3,7 +3,7 @@
  * Provides responsive behaviors to HTML details elements.
  */

-(function ($, Drupal) {
+(function ($, Drupal, debounce) {

   'use strict';

@@ -17,22 +17,26 @@
    */
   Drupal.behaviors.responsiveDetails = {
     attach: function (context) {
-      var $statusDetails = $(context).find('.system-status-report__entry');
+      var $statusDetails = $(context).find('details').once('responsive-details');

       function handleResize() {
         if (window.matchMedia('(min-width:48em)').matches) {
-          $statusDetails.attr('open', true);
+          $statusDetails
+            .attr('open', true)
+            .children('summary')
+            .attr('aria-expanded', true);
         }
         else {
           // If user explicitly opened one, leave it alone.
           $statusDetails.find('summary[aria-pressed!=true]')
+            .attr('aria-expanded', false)
             .parent('details')
             .attr('open', false);
         }
       }

-      $(window).on('resize.details', Drupal.debounce(handleResize, 150)).trigger('resize.details');
+      $(window).on('resize.details', debounce(handleResize, 150)).trigger('resize.details');
     }
   };

-})(jQuery, Drupal);
+})(jQuery, Drupal, Drupal.debounce);
diff --git a/core/themes/seven/seven.libraries.yml b/core/themes/seven/seven.libraries.yml
index 1b05ab2..d78a103 100644
--- a/core/themes/seven/seven.libraries.yml
+++ b/core/themes/seven/seven.libraries.yml
@@ -84,6 +84,7 @@ drupal.responsive-detail:
   dependencies:
     - core/matchmedia
     - core/jquery
+    - core/jquery.once
     - core/drupal.debounce

 vertical-tabs: