diff --git a/core/events/events_toolbox_item_select.js b/core/events/events_toolbox_item_select.js
index 694e24d5d..ec587ad92 100644
--- a/core/events/events_toolbox_item_select.js
+++ b/core/events/events_toolbox_item_select.js
@@ -10,7 +10,8 @@
  */
 'use strict';
 
-goog.provide('Blockly.Events.ToolboxItemSelect');
+goog.module('Blockly.Events.ToolboxItemSelect');
+goog.module.declareLegacyNamespace();
 
 goog.require('Blockly.Events');
 goog.require('Blockly.Events.UiBase');
@@ -29,9 +30,9 @@ goog.require('Blockly.utils.object');
  * @extends {Blockly.Events.UiBase}
  * @constructor
  */
-Blockly.Events.ToolboxItemSelect = function(opt_oldItem, opt_newItem,
+const ToolboxItemSelect = function(opt_oldItem, opt_newItem,
     opt_workspaceId) {
-  Blockly.Events.ToolboxItemSelect.superClass_.constructor.call(
+  ToolboxItemSelect.superClass_.constructor.call(
       this, opt_workspaceId);
 
   /**
@@ -46,20 +47,20 @@ Blockly.Events.ToolboxItemSelect = function(opt_oldItem, opt_newItem,
    */
   this.newItem = opt_newItem;
 };
-Blockly.utils.object.inherits(Blockly.Events.ToolboxItemSelect, Blockly.Events.UiBase);
+Blockly.utils.object.inherits(ToolboxItemSelect, Blockly.Events.UiBase);
 
 /**
  * Type of this event.
  * @type {string}
  */
-Blockly.Events.ToolboxItemSelect.prototype.type = Blockly.Events.TOOLBOX_ITEM_SELECT;
+ToolboxItemSelect.prototype.type = Blockly.Events.TOOLBOX_ITEM_SELECT;
 
 /**
  * Encode the event as JSON.
  * @return {!Object} JSON representation.
  */
-Blockly.Events.ToolboxItemSelect.prototype.toJson = function() {
-  const json = Blockly.Events.ToolboxItemSelect.superClass_.toJson.call(this);
+ToolboxItemSelect.prototype.toJson = function() {
+  const json = ToolboxItemSelect.superClass_.toJson.call(this);
   json['oldItem'] = this.oldItem;
   json['newItem'] = this.newItem;
   return json;
@@ -69,11 +70,13 @@ Blockly.Events.ToolboxItemSelect.prototype.toJson = function() {
  * Decode the JSON event.
  * @param {!Object} json JSON representation.
  */
-Blockly.Events.ToolboxItemSelect.prototype.fromJson = function(json) {
-  Blockly.Events.ToolboxItemSelect.superClass_.fromJson.call(this, json);
+ToolboxItemSelect.prototype.fromJson = function(json) {
+  ToolboxItemSelect.superClass_.fromJson.call(this, json);
   this.oldItem = json['oldItem'];
   this.newItem = json['newItem'];
 };
 
 Blockly.registry.register(Blockly.registry.Type.EVENT,
-    Blockly.Events.TOOLBOX_ITEM_SELECT, Blockly.Events.ToolboxItemSelect);
+    Blockly.Events.TOOLBOX_ITEM_SELECT, ToolboxItemSelect);
+
+exports = ToolboxItemSelect;
diff --git a/tests/deps.js b/tests/deps.js
index 1e9ef54f4..c5dd33a1d 100644
--- a/tests/deps.js
+++ b/tests/deps.js
@@ -42,7 +42,7 @@ goog.addDependency('../../core/events/events_click.js', ['Blockly.Events.Click']
 goog.addDependency('../../core/events/events_marker_move.js', ['Blockly.Events.MarkerMove'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
 goog.addDependency('../../core/events/events_selected.js', ['Blockly.Events.Selected'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
 goog.addDependency('../../core/events/events_theme_change.js', ['Blockly.Events.ThemeChange'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
-goog.addDependency('../../core/events/events_toolbox_item_select.js', ['Blockly.Events.ToolboxItemSelect'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
+goog.addDependency('../../core/events/events_toolbox_item_select.js', ['Blockly.Events.ToolboxItemSelect'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/events/events_trashcan_open.js', ['Blockly.Events.TrashcanOpen'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
 goog.addDependency('../../core/events/events_viewport.js', ['Blockly.Events.ViewportChange'], ['Blockly.Events', 'Blockly.Events.UiBase', 'Blockly.registry', 'Blockly.utils.object']);
 goog.addDependency('../../core/events/ui_events.js', ['Blockly.Events.Ui', 'Blockly.Events.UiBase'], ['Blockly.Events', 'Blockly.Events.Abstract', 'Blockly.registry', 'Blockly.utils.object']);