--- a/devtools/client/inspector/webpack.config.js
+++ b/devtools/client/inspector/webpack.config.js
@@ -72,17 +72,16 @@ module.exports = envConfig => {
           path.join(__dirname, "./webpack/devtools-utils-sham.js"),
         "devtools/shared/locales": path.join(__dirname, "../../shared/locales/en-US"),
         "devtools/shared/platform": path.join(__dirname, "../../shared/platform/content"),
         "devtools": path.join(__dirname, "../../"),
         "gcli": path.join(__dirname, "../../shared/gcli/source/lib/gcli"),
         "method": path.join(__dirname, "../../../addon-sdk/source/lib/method"),
         "modules/libpref/init/all":
           path.join(__dirname, "../../../modules/libpref/init/all.js"),
-        "sdk/system/unload": path.join(__dirname, "./webpack/system-unload-sham.js"),
         "sdk": path.join(__dirname, "../../../addon-sdk/source/lib/sdk"),
         "Services": path.join(__dirname, "../shared/shim/Services.js"),
         "toolkit/locales":
           path.join(__dirname, "../../../toolkit/locales/en-US/chrome/global"),
         "react": "devtools/client/shared/vendor/react",
         "react-dom": "devtools/client/shared/vendor/react-dom",
       },
     },

deleted file mode 100644
--- a/devtools/client/inspector/webpack/system-unload-sham.js
+++ /dev/null
@@ -1,11 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set ts=2 et sw=2 tw=80: */
-/* 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";
-
-module.exports = {
-  when: () => {},
-};