diff --git a/module/VuFind/src/VuFind/Theme/Root/Helper/SortFacetList.php b/module/VuFind/src/VuFind/Theme/Root/Helper/SortFacetList.php
index 808cd3d9d65e7bfc43d02c9e799cf00e2adb5fb9..3fd1522591131cce5801781070a54346c5861148 100644
--- a/module/VuFind/src/VuFind/Theme/Root/Helper/SortFacetList.php
+++ b/module/VuFind/src/VuFind/Theme/Root/Helper/SortFacetList.php
@@ -26,6 +26,8 @@
  * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
  * @link     http://vufind.org/wiki/building_a_recommendations_module Wiki
  */
+namespace VuFind\Theme\Root\Helper;
+use Zend\View\Helper\AbstractHelper;
 
 /**
  * Sort facet list view helper
@@ -36,27 +38,28 @@
  * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
  * @link     http://vufind.org/wiki/building_a_recommendations_module Wiki
  */
-class VuFind_Theme_Root_Helper_SortFacetList extends Zend_View_Helper_Abstract
+class SortFacetList extends AbstractHelper
 {
     /**
      * Turns facet information into an alphabetical list.
      *
-     * @param VF_Search_Base_Results $results     Search result object
-     * @param string                 $field       Facet field to sort
-     * @param array                  $list        Facet value list extract from the
-     * search result object's getFacetList method
-     * @param array                  $urlSettings Options to use to generate search
-     * URLs for individual facet values
+     * @param \VuFind\Search\Base\Results $results     Search result object
+     * @param string                      $field       Facet field to sort
+     * @param array                       $list        Facet value list extract from
+     * the search result object's getFacetList method
+     * @param array                       $searchRoute Route to use to generate
+     * search URLs for individual facet values
      *
      * @return array      Associative URL => description array sorted by description
      */
-    public function sortFacetList($results, $field, $list, $urlSettings)
+    public function __invoke($results, $field, $list, $searchRoute)
     {
         $facets = array();
         $results->setLimit($results->getDefaultLimit());    // avoid limit on URL
+        $urlHelper = $this->getView()->plugin('url');
         foreach ($list as $value) {
-            $url = $this->view->url($urlSettings, 'default', true) .
-                $results->getUrl()->addFacet($field, $value['value']);
+            $url = $urlHelper($searchRoute)
+                . $results->getUrl()->addFacet($field, $value['value']);
             $facets[$url] = $value['displayText'];
         }
         natcasesort($facets);
diff --git a/themes/root/theme.ini b/themes/root/theme.ini
index 58af66c089b16b6895aa37052b6efa6849dce308..dcd94e0bb2ba334c361e6ee923ea6b2a9dac3b30 100644
--- a/themes/root/theme.ini
+++ b/themes/root/theme.ini
@@ -10,6 +10,7 @@ helpers_to_register[] = "ImageLink"
 helpers_to_register[] = "MobileUrl"
 helpers_to_register[] = "OfflineMode"
 helpers_to_register[] = "SearchOptions"
+helpers_to_register[] = "SortFacetList"
 helpers_to_register[] = "SystemEmail"
 helpers_to_register[] = "TransEsc"
 helpers_to_register[] = "Translate"