diff --git a/core/interfaces/i_delete_area.js b/core/interfaces/i_delete_area.js
index 31f53350e..923c0bd7c 100644
--- a/core/interfaces/i_delete_area.js
+++ b/core/interfaces/i_delete_area.js
@@ -12,7 +12,8 @@
 
 'use strict';
 
-goog.provide('Blockly.IDeleteArea');
+goog.module('Blockly.IDeleteArea');
+goog.module.declareLegacyNamespace();
 
 goog.require('Blockly.IDragTarget');
 
@@ -25,7 +26,7 @@ goog.requireType('Blockly.IDraggable');
  * @extends {Blockly.IDragTarget}
  * @interface
  */
-Blockly.IDeleteArea = function() {};
+const IDeleteArea = function() {};
 
 /**
  * Returns whether the provided block or bubble would be deleted if dropped on
@@ -39,4 +40,6 @@ Blockly.IDeleteArea = function() {};
  * @return {boolean} Whether the element provided would be deleted if dropped on
  *     this area.
  */
-Blockly.IDeleteArea.prototype.wouldDelete;
+IDeleteArea.prototype.wouldDelete;
+
+exports = IDeleteArea;
diff --git a/tests/deps.js b/tests/deps.js
index c23b3f10c..234dbe062 100644
--- a/tests/deps.js
+++ b/tests/deps.js
@@ -83,7 +83,7 @@ goog.addDependency('../../core/interfaces/i_connection_checker.js', ['Blockly.IC
 goog.addDependency('../../core/interfaces/i_contextmenu.js', ['Blockly.IContextMenu'], []);
 goog.addDependency('../../core/interfaces/i_copyable.js', ['Blockly.ICopyable'], []);
 goog.addDependency('../../core/interfaces/i_deletable.js', ['Blockly.IDeletable'], [], {'lang': 'es6', 'module': 'goog'});
-goog.addDependency('../../core/interfaces/i_delete_area.js', ['Blockly.IDeleteArea'], ['Blockly.IDragTarget']);
+goog.addDependency('../../core/interfaces/i_delete_area.js', ['Blockly.IDeleteArea'], ['Blockly.IDragTarget'], {'lang': 'es6', 'module': 'goog'});
 goog.addDependency('../../core/interfaces/i_drag_target.js', ['Blockly.IDragTarget'], ['Blockly.IComponent']);
 goog.addDependency('../../core/interfaces/i_draggable.js', ['Blockly.IDraggable'], ['Blockly.IDeletable']);
 goog.addDependency('../../core/interfaces/i_flyout.js', ['Blockly.IFlyout'], []);