diff --git a/core/misc/vertical-tabs.css b/core/misc/vertical-tabs.css
index cf6cca6..6feffc0 100644
--- a/core/misc/vertical-tabs.css
+++ b/core/misc/vertical-tabs.css
@@ -66,3 +66,7 @@ div.vertical-tabs {
   -webkit-box-sizing: border-box;
   box-sizing: border-box;
 }
+
+.vertical-tab-button-error a {
+  border: 1px solid #FC6F5D;
+}
diff --git a/core/misc/vertical-tabs.js b/core/misc/vertical-tabs.js
index a9450a8..b977013 100644
--- a/core/misc/vertical-tabs.js
+++ b/core/misc/vertical-tabs.js
@@ -192,8 +192,13 @@ Drupal.verticalTab.prototype = {
  *   - summary: The jQuery element that contains the tab summary
  */
 Drupal.theme.verticalTab = function (settings) {
+  var class_name = 'vertical-tab-button';
+  if ($('.error', settings.fieldset).length>0) {
+   class_name += ' vertical-tab-button-error';
+  }
+
   var tab = {};
-  tab.item = $('<li class="vertical-tab-button" tabindex="-1"></li>')
+  tab.item = $('<li class="'+class_name+'" tabindex="-1"></li>')
     .append(tab.link = $('<a href="#"></a>')
       .append(tab.title = $('<strong></strong>').text(settings.title))
       .append(tab.summary = $('<span class="summary"></span>')