--- a/devtools/shared/fronts/emulation.js
+++ b/devtools/shared/fronts/emulation.js
@@ -1,14 +1,14 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
-const { Front, FrontClass } = require("devtools/shared/protocol");
+const { Front, FrontClassWithSpec } = require("devtools/shared/protocol");
 const { emulationSpec } = require("devtools/shared/specs/emulation");
 
 /**
  * The corresponding Front object for the EmulationActor.
  */
 const EmulationFront = FrontClassWithSpec(emulationSpec, {
   initialize: function (client, form) {
     Front.prototype.initialize.call(this, client);