diff --git a/cms/static/cms/js/widgets/forms.apphookselect.js b/cms/static/cms/js/widgets/forms.apphookselect.js
index e2d7c1278ba..38a2a9e2c90 100644
--- a/cms/static/cms/js/widgets/forms.apphookselect.js
+++ b/cms/static/cms/js/widgets/forms.apphookselect.js
@@ -10,39 +10,40 @@ __webpack_public_path__ = require('../modules/get-dist-path')('bundle.forms.apph
 // #############################################################################
 // APP HOOK SELECT
 require.ensure([], function (require) {
-    var $ = require('jquery');
-    var apphookData = {
+    const $ = require('jquery');
+    let apphookData = {
         apphooks_configuration: {},
         apphooks_configuration_value: undefined,
         apphooks_configuration_url: {}
     };
-    var dataElement = document.querySelector('script[data-cms-widget-applicationconfigselect]');
-
-    if (dataElement) {
-        apphookData = JSON.parse(dataElement.querySelector('script').textContent);
-    }
-
-    var apphooks_configuration = apphookData.apphooks_configuration || {};
 
     // shorthand for jQuery(document).ready();
     $(function () {
-        var appHooks = $('#application_urls, #id_application_urls');
-        var selected = appHooks.find('option:selected');
-        var appNsRow = $('.form-row.application_namespace, .form-row.field-application_namespace');
-        var appNs = appNsRow.find('#application_namespace, #id_application_namespace');
-        var appCfgsRow = $('.form-row.application_configs, .form-row.field-application_configs');
-        var appCfgs = appCfgsRow.find('#application_configs, #id_application_configs');
-        var appCfgsAdd = appCfgsRow.find('#add_application_configs');
-        var original_ns = appNs.val();
+        const dataElement = document.querySelector('div[data-cms-widget-applicationconfigselect]');
+
+        if (dataElement) {
+            apphookData = JSON.parse(dataElement.querySelector('script').textContent);
+        }
+
+        const apphooks_configuration = apphookData.apphooks_configuration || {};
+
+        const appHooks = $('#application_urls, #id_application_urls');
+        const selected = appHooks.find('option:selected');
+        const appNsRow = $('.form-row.application_namespace, .form-row.field-application_namespace');
+        const appNs = appNsRow.find('#application_namespace, #id_application_namespace');
+        const appCfgsRow = $('.form-row.application_configs, .form-row.field-application_configs');
+        const appCfgs = appCfgsRow.find('#application_configs, #id_application_configs');
+        const appCfgsAdd = appCfgsRow.find('#add_application_configs');
+        const original_ns = appNs.val();
 
         // Shows / hides namespace / config selection widgets depending on the user input
         appHooks.setupNamespaces = function () {
-            var opt = $(this).find('option:selected');
+            const opt = $(this).find('option:selected');
 
             if ($(appCfgs).length > 0 && apphooks_configuration[opt.val()]) {
                 appCfgs.html('');
-                for (var i = 0; i < apphooks_configuration[opt.val()].length; i++) {
-                    var selectedCfgs = '';
+                for (let i = 0; i < apphooks_configuration[opt.val()].length; i++) {
+                    let selectedCfgs = '';
 
                     if (apphooks_configuration[opt.val()][i][0] === apphookData.apphooks_configuration_value) {
                         selectedCfgs = 'selected="selected"';
@@ -58,7 +59,8 @@ require.ensure([], function (require) {
                     // exists, and if it does - we add `_popup` ourselves, because otherwise the popup with
                     // apphook creation form will not be dismissed correctly
                     (window.showRelatedObjectPopup ? '?_popup=1' : ''));
-                appCfgsAdd.on('click', function () {
+                appCfgsAdd.on('click', function (ev) {
+                    ev.preventDefault();
                     window.showAddAnotherPopup(this);
                 });
                 appCfgsRow.removeClass('hidden');