--- a/browser/base/content/test/general/browser_bug567306.js
+++ b/browser/base/content/test/general/browser_bug567306.js
@@ -1,14 +1,12 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
-var {Ci: interfaces, Cc: classes} = Components;
-
 var HasFindClipboard = Services.clipboard.supportsFindClipboard();
 
 add_task(async function() {
   let newwindow = await BrowserTestUtils.openNewBrowserWindow();
 
   let selectedBrowser = newwindow.gBrowser.selectedBrowser;
   await new Promise((resolve, reject) => {
     BrowserTestUtils.waitForContentEvent(selectedBrowser, "pageshow", true, (event) => {

--- a/browser/components/preferences/in-content/main.js
+++ b/browser/components/preferences/in-content/main.js
@@ -678,17 +678,16 @@ var gMainPane = {
       let separateProfileModeCheckbox = document.getElementById("separateProfileMode");
       let button_index = confirmRestartPrompt(separateProfileModeCheckbox.checked,
         0, false, true);
       switch (button_index) {
         case CONFIRM_RESTART_PROMPT_CANCEL:
           revertCheckbox();
           return;
         case CONFIRM_RESTART_PROMPT_RESTART_NOW:
-          const Cc = Components.classes, Ci = Components.interfaces;
           let cancelQuit = Cc["@mozilla.org/supports-PRBool;1"]
             .createInstance(Ci.nsISupportsPRBool);
           Services.obs.notifyObservers(cancelQuit, "quit-application-requested",
             "restart");
           if (!cancelQuit.data) {
             createOrRemoveSpecialDevEditionFile(quitApp);
             return;
           }
@@ -881,21 +880,18 @@ var gMainPane = {
     let prefName = "pref.browser.homepage.disable_button.current_page";
     if (Preferences.get(prefName).locked)
       return;
 
     useCurrent.disabled = !tabs.length;
   },
 
   _getTabsForHomePage() {
-    var win;
     var tabs = [];
-
-    const Cc = Components.classes, Ci = Components.interfaces;
-    win = Services.wm.getMostRecentWindow("navigator:browser");
+    var win = Services.wm.getMostRecentWindow("navigator:browser");
 
     if (win && win.document.documentElement
       .getAttribute("windowtype") == "navigator:browser") {
       // We should only include visible & non-pinned tabs
 
       tabs = win.gBrowser.visibleTabs.slice(win.gBrowser._numPinnedTabs);
       tabs = tabs.filter(this.isNotAboutPreferences);
     }

--- a/chrome/test/unit/test_abi.js
+++ b/chrome/test/unit/test_abi.js
@@ -3,18 +3,18 @@ updateAppInfo({
   name: "XPCShell",
   ID: "{39885e5f-f6b4-4e2a-87e5-6259ecf79011}",
   version: "5",
   platformVersion: "1.9",
 });
 
 registerManifests([do_get_file("data/test_abi.manifest")]);
 
-const catman = Components.classes["@mozilla.org/categorymanager;1"].
-  getService(Components.interfaces.nsICategoryManager);
+const catman = Cc["@mozilla.org/categorymanager;1"].
+  getService(Ci.nsICategoryManager);
 
 function is_registered(name) {
   try {
     var d = catman.getCategoryEntry("abitest", name);
     return d == "found";
   } catch (e) {
     return false;
   }

--- a/mobile/android/chrome/content/aboutAddons.js
+++ b/mobile/android/chrome/content/aboutAddons.js
@@ -1,18 +1,16 @@
 /* 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";
 
 /* globals gChromeWin */
 
-var Ci = Components.interfaces, Cc = Components.classes, Cu = Components.utils;
-
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/AddonManager.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const AMO_ICON = "chrome://browser/skin/images/amo-logo.png";
 const UPDATE_INDICATOR = "chrome://browser/skin/images/extension-update.svg";
 
 var gStringBundle = Services.strings.createBundle("chrome://browser/locale/aboutAddons.properties");

--- a/mobile/android/chrome/content/aboutLogins.js
+++ b/mobile/android/chrome/content/aboutLogins.js
@@ -1,14 +1,12 @@
 /* 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/. */
 
-var Ci = Components.interfaces, Cc = Components.classes, Cu = Components.utils;
-
 ChromeUtils.import("resource://services-common/utils.js"); /* global: CommonUtils */
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/TelemetryStopwatch.jsm");
 
 XPCOMUtils.defineLazyGetter(window, "gChromeWin", () =>
   window.QueryInterface(Ci.nsIInterfaceRequestor)
     .getInterface(Ci.nsIWebNavigation)

--- a/testing/xpcshell/dbg-actors.js
+++ b/testing/xpcshell/dbg-actors.js
@@ -2,16 +2,17 @@
  * 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";
 
 /* import-globals-from ../../devtools/server/main.js */
 /* eslint "mozilla/use-chromeutils-import": ["error", {allowCu: true}] */
 
+// eslint-disable-next-line mozilla/no-define-cc-etc
 const Cu = Components.utils;
 const { Promise } = Cu.import("resource://gre/modules/Promise.jsm", {});
 var { Services } = Cu.import("resource://gre/modules/Services.jsm", {});
 const { devtools } = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const { RootActor } = devtools.require("devtools/server/actors/root");
 const { BrowserTabList } = devtools.require("devtools/server/actors/webbrowser");
 
 /**

--- a/toolkit/components/osfile/modules/osfile_shared_allthreads.jsm
+++ b/toolkit/components/osfile/modules/osfile_shared_allthreads.jsm
@@ -17,22 +17,16 @@
  * - a few additional utilities.
  */
 
 /* eslint-env worker */
 
 // Boilerplate used to be able to import this module both from the main
 // thread and from worker threads.
 
-// Since const is lexically scoped, hoist the
-// conditionally-useful definition ourselves.
-const Cu = typeof Components != "undefined" ? Components.utils : undefined;
-const Ci = typeof Components != "undefined" ? Components.interfaces : undefined;
-const Cc = typeof Components != "undefined" ? Components.classes : undefined;
-
 /**
  * A constructor for messages that require transfers instead of copies.
  *
  * See BasePromiseWorker.Meta.
  *
  * @constructor
  */
 var Meta;

--- a/toolkit/components/reader/AboutReader.jsm
+++ b/toolkit/components/reader/AboutReader.jsm
@@ -1,16 +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";
 
-var Ci = Components.interfaces, Cc = Components.classes, Cu = Components.utils;
-
 this.EXPORTED_SYMBOLS = [ "AboutReader" ];
 
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 ChromeUtils.import("resource://gre/modules/ReaderMode.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 ChromeUtils.defineModuleGetter(this, "AsyncPrefs", "resource://gre/modules/AsyncPrefs.jsm");

--- a/toolkit/modules/PopupNotifications.jsm
+++ b/toolkit/modules/PopupNotifications.jsm
@@ -1,16 +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/. */
 
 this.EXPORTED_SYMBOLS = ["PopupNotifications"];
 
-var Cc = Components.classes, Ci = Components.interfaces, Cu = Components.utils;
-
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
 ChromeUtils.import("resource://gre/modules/PromiseUtils.jsm");
 
 const NOTIFICATION_EVENT_DISMISSED = "dismissed";
 const NOTIFICATION_EVENT_REMOVED = "removed";
 const NOTIFICATION_EVENT_SHOWING = "showing";
 const NOTIFICATION_EVENT_SHOWN = "shown";

--- a/toolkit/modules/Promise-backend.js
+++ b/toolkit/modules/Promise-backend.js
@@ -39,19 +39,21 @@
 // that Components is not defined in worker threads, so no instance of Cu can
 // be obtained.
 
 // As this can be loaded in several ways, allow require and module to be defined.
 /* global module:false require:false */
 // This is allowed in workers.
 /* global setImmediate:false */
 
+/* eslint-disable mozilla/no-define-cc-etc */
 var Cu = this.require ? require("chrome").Cu : Components.utils;
 var Cc = this.require ? require("chrome").Cc : Components.classes;
 var Ci = this.require ? require("chrome").Ci : Components.interfaces;
+/* eslint-enable mozilla/no-define-cc-etc */
 // If we can access Components, then we use it to capture an async
 // parent stack trace; see scheduleWalkerLoop.  However, as it might
 // not be available (see above), users of this must check it first.
 var Components_ = this.require ? require("chrome").components : Components;
 
 // If Cu is defined, use it to lazily define the FinalizationWitnessService.
 if (Cu) {
   // If we're in a devtools module environment, ChromeUtils won't exist.

--- a/tools/code-coverage/tests/xpcshell/test_basic_child_and_parent.js
+++ b/tools/code-coverage/tests/xpcshell/test_basic_child_and_parent.js
@@ -2,16 +2,16 @@
  * 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/. */
 
 function run_test() {
   do_load_child_test_harness();
   do_test_pending();
 
   sendCommand("let v = 'test';", function() {
-      let codeCoverage = Components.classes["@mozilla.org/tools/code-coverage;1"].getService(Components.interfaces.nsICodeCoverage);
+      let codeCoverage = Cc["@mozilla.org/tools/code-coverage;1"].getService(Ci.nsICodeCoverage);
 
       codeCoverage.dumpCounters();
       codeCoverage.resetCounters();
 
       do_test_finished();
   });
 }

--- a/tools/quitter/QuitterObserver.js
+++ b/tools/quitter/QuitterObserver.js
@@ -9,17 +9,17 @@ const CHILD_SCRIPT = "chrome://quitter/c
 
 /* XPCOM gunk */
 function QuitterObserver() {}
 
 QuitterObserver.prototype = {
   classDescription: "Quitter Observer for use in testing.",
   classID:          Components.ID("{c235a986-5ac1-4f28-ad73-825dae9bad90}"),
   contractID:       "@mozilla.org/quitter-observer;1",
-  QueryInterface:   XPCOMUtils.generateQI([Components.interfaces.nsIObserver]),
+  QueryInterface:   XPCOMUtils.generateQI([Ci.nsIObserver]),
   _xpcom_categories: [{category: "profile-after-change", service: true }],
   isFrameScriptLoaded: false,
 
   observe(aSubject, aTopic, aData) {
     if (aTopic == "profile-after-change") {
       this.init();
     } else if (!this.isFrameScriptLoaded &&
                aTopic == "chrome-document-global-created") {