diff --git a/core/misc/collapse.js b/core/misc/collapse.js
index 6aa2e25..0dd4246 100644
--- a/core/misc/collapse.js
+++ b/core/misc/collapse.js
@@ -11,13 +11,21 @@
     // Expand details if there are errors inside, or if it contains an
     // element that is targeted by the URI fragment identifier.
     var anchor = location.hash && location.hash !== '#' ? ', ' + location.hash : '';
-    if (this.$node.find('.error' + anchor).length) {
-      this.$node.attr('open', true);
+
+    this.$node.find('input, .error' + anchor).on('invalid', $.proxy(this.invalidHandler, this));
+
+    var $invalidTarget = this.$node.find('.error' + anchor);
+    if ($invalidTarget.length) {
+      $invalidTarget.trigger('invalid');
     }
-    // Initialize and setup the summary,
-    this.setupSummary();
-    // Initialize and setup the legend.
-    this.setupLegend();
+
+    if (!Modernizr.details) {
+      // Initialize and setup the summary,
+      this.setupSummary();
+      // Initialize and setup the legend.
+      this.setupLegend();
+    }
+
   }
 
   /**
@@ -82,33 +90,41 @@
     /**
      * Toggle the visibility of a details element using smooth animations.
      */
-    toggle: function () {
-      var isOpen = !!this.$node.attr('open');
+    toggle: function (isOpen) {
+      if (typeof isOpen == 'undefined') {
+        isOpen = !this.$node.attr('open');
+      }
       var $summaryPrefix = this.$node.find('> summary span.details-summary-prefix');
       if (isOpen) {
-        $summaryPrefix.html(Drupal.t('Show'));
+        $summaryPrefix.html(Drupal.t('Hide'));
       }
       else {
-        $summaryPrefix.html(Drupal.t('Hide'));
+        $summaryPrefix.html(Drupal.t('Show'));
       }
-      this.$node.attr('open', !isOpen);
+      this.$node.attr('open', isOpen);
+    },
+    /**
+     * Handle invalid event
+     */
+    invalidHandler: function () {
+      this.toggle(true);
     }
   });
 
   Drupal.behaviors.collapse = {
     attach: function (context) {
-      if (Modernizr.details) {
-        return;
-      }
-      var $collapsibleDetails = $(context).find('details').once('collapse').addClass('collapse-processed');
+      var $collapsibleDetails = $(context).find('details').once('collapse');
       if ($collapsibleDetails.length) {
+        if (!Modernizr.details) {
+          $collapsibleDetails.addClass('collapse-processed');
+        }
+
         for (var i = 0; i < $collapsibleDetails.length; i++) {
           CollapsibleDetails.instances.push(new CollapsibleDetails($collapsibleDetails[i]));
         }
       }
     }
   };
-
   // Expose constructor in the public space.
   Drupal.CollapsibleDetails = CollapsibleDetails;