diff --git a/core/delete_area.js b/core/delete_area.js
index 384136a05..55eb61a34 100644
--- a/core/delete_area.js
+++ b/core/delete_area.js
@@ -12,23 +12,26 @@
 
 'use strict';
 
-goog.provide('Blockly.DeleteArea');
+goog.module('Blockly.DeleteArea');
+goog.module.declareLegacyNamespace();
 
-goog.require('Blockly.BlockSvg');
-goog.require('Blockly.DragTarget');
-goog.require('Blockly.IDeleteArea');
-
-goog.requireType('Blockly.IDraggable');
+const BlockSvg = goog.require('Blockly.BlockSvg');
+const DragTarget = goog.require('Blockly.DragTarget');
+/* eslint-disable-next-line no-unused-vars */
+const IDeleteArea = goog.require('Blockly.IDeleteArea');
+/* eslint-disable-next-line no-unused-vars */
+const IDraggable = goog.requireType('Blockly.IDraggable');
+const {inherits} = goog.require('Blockly.utils.object');
 
 /**
  * Abstract class for a component that can delete a block or bubble that is
  * dropped on top of it.
- * @extends {Blockly.DragTarget}
- * @implements {Blockly.IDeleteArea}
+ * @extends {DragTarget}
+ * @implements {IDeleteArea}
  * @constructor
  */
-Blockly.DeleteArea = function() {
-  Blockly.DeleteArea.superClass_.constructor.call(this);
+const DeleteArea = function() {
+  DeleteArea.superClass_.constructor.call(this);
 
   /**
    * Whether the last block or bubble dragged over this delete area would be
@@ -39,24 +42,24 @@ Blockly.DeleteArea = function() {
    */
   this.wouldDelete_ = false;
 };
-Blockly.utils.object.inherits(Blockly.DeleteArea, Blockly.DragTarget);
+inherits(DeleteArea, DragTarget);
 
 /**
  * Returns whether the provided block or bubble would be deleted if dropped on
  * this area.
  * This method should check if the element is deletable and is always called
  * before onDragEnter/onDragOver/onDragExit.
- * @param {!Blockly.IDraggable} element The block or bubble currently being
+ * @param {!IDraggable} element The block or bubble currently being
  *   dragged.
  * @param {boolean} couldConnect Whether the element could could connect to
  *     another.
  * @return {boolean} Whether the element provided would be deleted if dropped on
  *     this area.
  */
-Blockly.DeleteArea.prototype.wouldDelete = function(element, couldConnect) {
-  if (element instanceof Blockly.BlockSvg) {
-    var block = /** @type {Blockly.BlockSvg} */ (element);
-    var couldDeleteBlock = !block.getParent() && block.isDeletable();
+DeleteArea.prototype.wouldDelete = function(element, couldConnect) {
+  if (element instanceof BlockSvg) {
+    const block = /** @type {BlockSvg} */ (element);
+    const couldDeleteBlock = !block.getParent() && block.isDeletable();
     this.updateWouldDelete_(couldDeleteBlock && !couldConnect);
   } else {
     this.updateWouldDelete_(element.isDeletable());
@@ -69,6 +72,8 @@ Blockly.DeleteArea.prototype.wouldDelete = function(element, couldConnect) {
  * @param {boolean} wouldDelete The new value for the wouldDelete state.
  * @protected
  */
-Blockly.DeleteArea.prototype.updateWouldDelete_ = function(wouldDelete) {
+DeleteArea.prototype.updateWouldDelete_ = function(wouldDelete) {
   this.wouldDelete_ = wouldDelete;
 };
+
+exports = DeleteArea;
diff --git a/tests/deps.js b/tests/deps.js
index da56c39f2..234771c13 100644
--- a/tests/deps.js
+++ b/tests/deps.js
@@ -28,7 +28,7 @@ goog.addDependency('../../core/contextmenu.js', ['Blockly.ContextMenu'], ['Block
 goog.addDependency('../../core/contextmenu_items.js', ['Blockly.ContextMenuItems'], ['Blockly.ContextMenuRegistry', 'Blockly.Events', 'Blockly.constants', 'Blockly.inputTypes'], {'lang': 'es5'});
 goog.addDependency('../../core/contextmenu_registry.js', ['Blockly.ContextMenuRegistry'], [], {'lang': 'es5'});
 goog.addDependency('../../core/css.js', ['Blockly.Css'], [], {'lang': 'es6', 'module': 'goog'});
-goog.addDependency('../../core/delete_area.js', ['Blockly.DeleteArea'], ['Blockly.BlockSvg', 'Blockly.DragTarget', 'Blockly.IDeleteArea']);
+goog.addDependency('../../core/delete_area.js', ['Blockly.DeleteArea'], ['Blockly.BlockSvg', 'Blockly.DragTarget', 'Blockly.IDeleteArea', 'Blockly.utils.object'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/drag_target.js', ['Blockly.DragTarget'], ['Blockly.IDragTarget'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/dropdowndiv.js', ['Blockly.DropDownDiv'], ['Blockly.utils.Rect', 'Blockly.utils.dom', 'Blockly.utils.math', 'Blockly.utils.style']);
 goog.addDependency('../../core/events/block_events.js', ['Blockly.Events.BlockBase', 'Blockly.Events.BlockChange', 'Blockly.Events.BlockCreate', 'Blockly.Events.BlockDelete', 'Blockly.Events.BlockMove', 'Blockly.Events.Change', 'Blockly.Events.Create', 'Blockly.Events.Delete', 'Blockly.Events.Move'], ['Blockly.Events', 'Blockly.Events.Abstract', 'Blockly.Xml', 'Blockly.connectionTypes', 'Blockly.registry', 'Blockly.utils.Coordinate', 'Blockly.utils.object', 'Blockly.utils.xml']);