diff --git a/browser/base/content/aboutDialog.js b/browser/base/content/aboutDialog.js
index e3358b2a401..461375ec3bd 100644
--- a/browser/base/content/aboutDialog.js
+++ b/browser/base/content/aboutDialog.js
@@ -194,7 +194,7 @@ appUpdater.prototype =
   // true when updating in background is enabled.
   get backgroundUpdateEnabled() {
     return this.updateEnabled &&
-           Services.prefs.getBoolPref("app.update.stage.enabled");
+           gAppUpdater.aus.canStageUpdates;
   },
 
   // true when updating is automatic.
diff --git a/toolkit/mozapps/update/content/updates.js b/toolkit/mozapps/update/content/updates.js
index 304416e45bb..c6548fb653e 100644
--- a/toolkit/mozapps/update/content/updates.js
+++ b/toolkit/mozapps/update/content/updates.js
@@ -15,7 +15,6 @@ const CoR = Components.results;
 
 const XMLNS_XUL               = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
 
-const PREF_APP_UPDATE_BACKGROUND         = "app.update.stage.enabled";
 const PREF_APP_UPDATE_BACKGROUNDERRORS   = "app.update.backgroundErrors";
 const PREF_APP_UPDATE_BILLBOARD_TEST_URL = "app.update.billboard.test_url";
 const PREF_APP_UPDATE_CERT_ERRORS        = "app.update.cert.errors";
@@ -1581,7 +1580,9 @@ var gDownloadingPage = {
       LOG("gDownloadingPage", "onStopRequest - patch verification succeeded");
       // If the background update pref is set, we should wait until the update
       // is actually staged in the background.
-      if (getPref("getBoolPref", PREF_APP_UPDATE_BACKGROUND, false)) {
+      var aus = CoC["@mozilla.org/updates/update-service;1"].
+                getService(CoI.nsIApplicationUpdateService);
+      if (aus.canStageUpdates) {
         this._setUpdateApplying();
       } else {
         this.cleanUp();
diff --git a/toolkit/mozapps/update/nsIUpdateService.idl b/toolkit/mozapps/update/nsIUpdateService.idl
index 374f6796279..72016515199 100644
--- a/toolkit/mozapps/update/nsIUpdateService.idl
+++ b/toolkit/mozapps/update/nsIUpdateService.idl
@@ -352,7 +352,7 @@ interface nsIUpdateChecker : nsISupports
  * background update checks and provides utilities for selecting and
  * downloading update patches.
  */
-[scriptable, uuid(7bd62f69-f604-484b-b97c-e7229d7a3ee8)]
+[scriptable, uuid(900b4a18-3bef-4f3e-bcf5-84dce0021c6d)]
 interface nsIApplicationUpdateService : nsISupports
 {
   /**
@@ -422,6 +422,11 @@ interface nsIApplicationUpdateService : nsISupports
    * privileges to the install directory.
    */
   readonly attribute boolean canApplyUpdates;
+
+  /**
+   * Whether the Update Service is able to stage updates.
+   */
+  readonly attribute boolean canStageUpdates;
 };
 
 /**
diff --git a/toolkit/mozapps/update/nsUpdateService.js b/toolkit/mozapps/update/nsUpdateService.js
index daf776ff221..95e479f529e 100644
--- a/toolkit/mozapps/update/nsUpdateService.js
+++ b/toolkit/mozapps/update/nsUpdateService.js
@@ -2046,6 +2046,13 @@ UpdateService.prototype = {
     return gCanApplyUpdates;
   },
 
+  /**
+   * See nsIUpdateService.idl
+   */
+  get canStageUpdates() {
+    return gCanStageUpdates;
+  },
+
   /**
    * See nsIUpdateService.idl
    */