diff --git a/core/themes/seven/js/nav-tabs.js b/core/themes/seven/js/nav-tabs.js
index d78697f..9d73b37 100644
--- a/core/themes/seven/js/nav-tabs.js
+++ b/core/themes/seven/js/nav-tabs.js
@@ -8,6 +8,7 @@
   function init (i, tab) {
     var $tab = $(tab);
     var $target = $tab.find('[data-drupal-nav-tabs-target]');
+    var isCollapsible = $tab.hasClass('is-collapsible');
 
     function openMenu (e) {
       $target.toggleClass('is-open');
@@ -17,7 +18,9 @@
       $tab.addClass('is-horizontal');
       var isHorizontal = $tab.parent().width() > $tab.intrinsic('width');
       $tab.toggleClass('is-horizontal', isHorizontal);
-      $tab.toggleClass('is-collapse-enabled', !isHorizontal);
+      if(isCollapsible) {
+        $tab.toggleClass('is-collapse-enabled', !isHorizontal);
+      }
       if (isHorizontal) {
         $target.removeClass('is-open');
       }
diff --git a/core/themes/seven/seven.theme b/core/themes/seven/seven.theme
index 131333c..7718f11 100644
--- a/core/themes/seven/seven.theme
+++ b/core/themes/seven/seven.theme
@@ -84,7 +84,7 @@ function seven_menu_local_tasks(&$variables) {
   if (!empty($variables['primary'])) {
     drupal_add_library('seven', 'drupal.nav-tabs', FALSE);
     $variables['primary']['#prefix'] = '<h2 class="visually-hidden">' . t('Primary tabs') . '</h2>';
-    $variables['primary']['#prefix'] .= '<nav role="navigation" class="is-horizontal" data-drupal-nav-tabs>';
+    $variables['primary']['#prefix'] .= '<nav role="navigation" class="is-horizontal is-collapsible" data-drupal-nav-tabs>';
     $variables['primary']['#prefix'] .= '<button class="reset-appearance tabs__tab tabs__trigger" data-drupal-nav-tabs-trigger>&bull;&bull;&bull;</button>';
     $variables['primary']['#prefix'] .= '<ul class="tabs primary clearfix"  data-drupal-nav-tabs-target>';
     $variables['primary']['#suffix'] = '</ul>';
@@ -95,7 +95,7 @@ function seven_menu_local_tasks(&$variables) {
     drupal_add_library('seven', 'drupal.nav-tabs', FALSE);
     $variables['secondary']['#prefix'] = '<h2 class="visually-hidden">' . t('Secondary tabs') . '</h2>';
     $variables['secondary']['#prefix'] .= '<nav role="navigation" class="is-horizontal" data-drupal-nav-tabs>';
-    $variables['secondary']['#prefix'] .= '<ul class="tabs secondary clearfix" data-drupal-nav-tabs-target>';
+    $variables['secondary']['#prefix'] .= '<ul class="tabs secondary clearfix">';
     $variables['secondary']['#suffix'] = '</ul>';
     $variables['secondary']['#suffix'] .= '</nav>';
     $output .= drupal_render($variables['secondary']);
diff --git a/core/themes/seven/style.css b/core/themes/seven/style.css
index 2fa05c7..81a33dd 100644
--- a/core/themes/seven/style.css
+++ b/core/themes/seven/style.css
@@ -499,11 +499,13 @@ li.tabs__tab a {
 .tabs.secondary .tabs__tab {
   display: block;
   padding: 5px 15px 5px 16px;
-  border-bottom: 1px solid transparent;
-  border-left: 1px solid transparent;
   margin-left: -1px;
   color: #0074bd;
 }
+.is-horizontal .tabs.secondary .tabs__tab {
+  border-bottom: 1px solid transparent;
+  border-left: 1px solid transparent;
+}
 .tabs.secondary .tabs__tab + .tabs__tab {
   border-top: 1px solid #d9d8d4;
 }