--- a/devtools/shared/client/main.js
+++ b/devtools/shared/client/main.js
@@ -5,17 +5,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const { Ci, Cu, components } = require("chrome");
 const Services = require("Services");
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
 
-const promise = Cu.import("resource://devtools/shared/deprecated-sync-thenables.js", {}).Promise;
+const promise = require("promise");
 
 loader.lazyRequireGetter(this, "events", "sdk/event/core");
 loader.lazyRequireGetter(this, "WebConsoleClient", "devtools/shared/webconsole/client", true);
 loader.lazyRequireGetter(this, "DebuggerSocket", "devtools/shared/security/socket", true);
 loader.lazyRequireGetter(this, "Authentication", "devtools/shared/security/auth");
 
 const noop = () => {};