--- a/browser/components/preferences/in-content/tests/browser_advanced_update.js
+++ b/browser/components/preferences/in-content/tests/browser_advanced_update.js
@@ -9,41 +9,37 @@ const uuidGenerator = Cc["@mozilla.org/u
 
 const mockUpdateManager = {
   contractId: "@mozilla.org/updates/update-manager;1",
 
   _mockClassId: uuidGenerator.generateUUID(),
 
   _originalClassId: "",
 
-  _originalFactory: null,
-
   QueryInterface: ChromeUtils.generateQI([Ci.nsIUpdateManager]),
 
   createInstance(outer, iiD) {
     if (outer) {
       throw Cr.NS_ERROR_NO_AGGREGATION;
     }
     return this.QueryInterface(iiD);
   },
 
   register() {
     let registrar = Cm.QueryInterface(Ci.nsIComponentRegistrar);
     if (!registrar.isCIDRegistered(this._mockClassId)) {
       this._originalClassId = registrar.contractIDToCID(this.contractId);
-      this._originalFactory = Cm.getClassObject(Cc[this.contractId], Ci.nsIFactory);
-      registrar.unregisterFactory(this._originalClassId, this._originalFactory);
       registrar.registerFactory(this._mockClassId, "Unregister after testing", this.contractId, this);
     }
   },
 
   unregister() {
     let registrar = Cm.QueryInterface(Ci.nsIComponentRegistrar);
     registrar.unregisterFactory(this._mockClassId, this);
-    registrar.registerFactory(this._originalClassId, "", this.contractId, this._originalFactory);
+    registrar.registerFactory(this._originalClassId, "", this.contractId, null);
   },
 
   get updateCount() {
     return this._updates.length;
   },
 
   getUpdateAt(index) {
     return this._updates[index];

--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -220,18 +220,16 @@
 @RESPATH@/components/NetworkGeolocationProvider.js
 @RESPATH@/components/extensions.manifest
 @RESPATH@/components/addonManager.js
 @RESPATH@/components/amContentHandler.js
 @RESPATH@/components/amInstallTrigger.js
 @RESPATH@/components/amWebAPI.js
 #ifdef MOZ_UPDATER
 @RESPATH@/components/nsUpdateService.manifest
-@RESPATH@/components/nsUpdateService.js
-@RESPATH@/components/nsUpdateServiceStub.js
 #endif
 @RESPATH@/components/nsUpdateTimerManager.manifest
 @RESPATH@/components/nsUpdateTimerManager.js
 @RESPATH@/components/utils.manifest
 @RESPATH@/components/simpleServices.js
 @RESPATH@/components/ProcessSingleton.manifest
 @RESPATH@/components/MainProcessSingleton.js
 @RESPATH@/components/ContentProcessSingleton.js

--- a/mobile/android/installer/package-manifest.in
+++ b/mobile/android/installer/package-manifest.in
@@ -151,18 +151,16 @@
 #endif
 
 @BINPATH@/components/WebVTT.manifest
 @BINPATH@/components/WebVTTParserWrapper.js
 
 #ifndef MOZ_GECKOVIEW_JAR
 #ifdef MOZ_UPDATER
 @BINPATH@/components/nsUpdateService.manifest
-@BINPATH@/components/nsUpdateService.js
-@BINPATH@/components/nsUpdateServiceStub.js
 #endif
 #endif
 
 @BINPATH@/components/ClearDataService.manifest
 @BINPATH@/components/ClearDataService.js
 
 @BINPATH@/components/nsUpdateTimerManager.manifest
 @BINPATH@/components/nsUpdateTimerManager.js

rename from toolkit/mozapps/update/nsUpdateService.js
rename to toolkit/mozapps/update/UpdateService.jsm
--- a/toolkit/mozapps/update/nsUpdateService.js
+++ b/toolkit/mozapps/update/UpdateService.jsm
@@ -4362,10 +4362,9 @@ UpdatePrompt.prototype = {
   },
 
   classDescription: "Update Prompt",
   contractID: "@mozilla.org/updates/update-prompt;1",
   classID: Components.ID("{27ABA825-35B5-4018-9FDD-F99250A0E722}"),
   QueryInterface: ChromeUtils.generateQI([Ci.nsIUpdatePrompt]),
 };
 
-var components = [UpdateService, Checker, UpdatePrompt, UpdateManager];
-this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);
+var EXPORTED_SYMBOLS = ["UpdateService", "Checker", "UpdatePrompt", "UpdateManager"];

rename from toolkit/mozapps/update/nsUpdateServiceStub.js
rename to toolkit/mozapps/update/UpdateServiceStub.jsm
--- a/toolkit/mozapps/update/nsUpdateServiceStub.js
+++ b/toolkit/mozapps/update/UpdateServiceStub.jsm
@@ -56,17 +56,17 @@ function UpdateServiceStub() {
   }
 }
 UpdateServiceStub.prototype = {
   observe() {},
   classID: Components.ID("{e43b0010-04ba-4da6-b523-1f92580bc150}"),
   QueryInterface: ChromeUtils.generateQI([Ci.nsIObserver]),
 };
 
-this.NSGetFactory = XPCOMUtils.generateNSGetFactory([UpdateServiceStub]);
+var EXPORTED_SYMBOLS = ["UpdateServiceStub"];
 
 /**
  * This function should be called when there are files in the old update
  * directory that may need to be migrated to the new update directory.
  */
 function migrateUpdateDirectory() {
   let sourceRootDir = FileUtils.getDir(KEY_OLD_UPDROOT, [], false);
   let destRootDir = FileUtils.getDir(KEY_UPDROOT, [], false);

new file mode 100644
--- /dev/null
+++ b/toolkit/mozapps/update/components.conf
@@ -0,0 +1,40 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+Classes = [
+    {
+        'cid': '{B3C290A6-3943-4B89-8BBE-C01EB7B3B311}',
+        'contract_ids': ['@mozilla.org/updates/update-service;1'],
+        'jsm': 'resource://gre/modules/UpdateService.jsm',
+        'constructor': 'UpdateService',
+    },
+    {
+        'cid': '{093C2356-4843-4C65-8709-D7DBCBBE7DFB}',
+        'contract_ids': ['@mozilla.org/updates/update-manager;1'],
+        'jsm': 'resource://gre/modules/UpdateService.jsm',
+        'constructor': 'UpdateManager',
+    },
+    {
+        'cid': '{898CDC9B-E43F-422F-9CC4-2F6291B415A3}',
+        'contract_ids': ['@mozilla.org/updates/update-checker;1'],
+        'jsm': 'resource://gre/modules/UpdateService.jsm',
+        'constructor': 'Checker',
+    },
+    {
+        'cid': '{27ABA825-35B5-4018-9FDD-F99250A0E722}',
+        'contract_ids': ['@mozilla.org/updates/update-prompt;1'],
+        'jsm': 'resource://gre/modules/UpdateService.jsm',
+        'constructor': 'UpdatePrompt',
+    },
+
+    {
+        'cid': '{e43b0010-04ba-4da6-b523-1f92580bc150}',
+        'contract_ids': ['@mozilla.org/updates/update-service-stub;1'],
+        'jsm': 'resource://gre/modules/UpdateServiceStub.jsm',
+        'constructor': 'UpdateServiceStub',
+        'categories': {'profile-after-change': 'nsUpdateServiceStub'},
+    },
+]

--- a/toolkit/mozapps/update/moz.build
+++ b/toolkit/mozapps/update/moz.build
@@ -12,22 +12,26 @@ DIRS += [
 
 XPIDL_SOURCES += [
     'nsIUpdateService.idl',
 ]
 
 TEST_DIRS += ['tests']
 
 EXTRA_COMPONENTS += [
-    'nsUpdateService.js',
     'nsUpdateService.manifest',
-    'nsUpdateServiceStub.js',
 ]
 
 EXTRA_JS_MODULES += [
     'UpdateListener.jsm',
+    'UpdateService.jsm',
+    'UpdateServiceStub.jsm',
     'UpdateTelemetry.jsm',
 ]
 
+XPCOM_MANIFESTS += [
+    'components.conf',
+]
+
 JAR_MANIFESTS += ['jar.mn']
 
 with Files('**'):
     BUG_COMPONENT = ('Toolkit', 'Application Update')

--- a/toolkit/mozapps/update/nsUpdateService.manifest
+++ b/toolkit/mozapps/update/nsUpdateService.manifest
@@ -1,12 +1,1 @@
-component {B3C290A6-3943-4B89-8BBE-C01EB7B3B311} nsUpdateService.js
-contract @mozilla.org/updates/update-service;1 {B3C290A6-3943-4B89-8BBE-C01EB7B3B311}
 category update-timer nsUpdateService @mozilla.org/updates/update-service;1,getService,background-update-timer,app.update.interval,43200,86400
-component {093C2356-4843-4C65-8709-D7DBCBBE7DFB} nsUpdateService.js
-contract @mozilla.org/updates/update-manager;1 {093C2356-4843-4C65-8709-D7DBCBBE7DFB}
-component {898CDC9B-E43F-422F-9CC4-2F6291B415A3} nsUpdateService.js
-contract @mozilla.org/updates/update-checker;1 {898CDC9B-E43F-422F-9CC4-2F6291B415A3}
-component {27ABA825-35B5-4018-9FDD-F99250A0E722} nsUpdateService.js
-contract @mozilla.org/updates/update-prompt;1 {27ABA825-35B5-4018-9FDD-F99250A0E722}
-component {e43b0010-04ba-4da6-b523-1f92580bc150} nsUpdateServiceStub.js
-contract @mozilla.org/updates/update-service-stub;1 {e43b0010-04ba-4da6-b523-1f92580bc150}
-category profile-after-change nsUpdateServiceStub @mozilla.org/updates/update-service-stub;1