--- a/browser/components/uitour/jar.mn
+++ b/browser/components/uitour/jar.mn
@@ -1,7 +1,6 @@
 # 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/.
 
 browser.jar:
        content/browser/content-UITour.js
-       content/browser/UITour-lib.js

--- a/browser/extensions/onboarding/content/onboarding.js
+++ b/browser/extensions/onboarding/content/onboarding.js
@@ -9,17 +9,17 @@
 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/Preferences.jsm");
 
 const ONBOARDING_CSS_URL = "resource://onboarding/onboarding.css";
 const ABOUT_HOME_URL = "about:home";
 const ABOUT_NEWTAB_URL = "about:newtab";
 const BUNDLE_URI = "chrome://onboarding/locale/onboarding.properties";
-const UITOUR_JS_URI = "chrome://browser/content/UITour-lib.js";
+const UITOUR_JS_URI = "resource://onboarding/lib/UITour-lib.js";
 const TOUR_AGENT_JS_URI = "resource://onboarding/onboarding-tour-agent.js";
 const BRAND_SHORT_NAME = Services.strings
                      .createBundle("chrome://branding/locale/brand.properties")
                      .GetStringFromName("brandShortName");
 
 /**
  * Add any number of tours, following the format
  * {

--- a/browser/extensions/onboarding/jar.mn
+++ b/browser/extensions/onboarding/jar.mn
@@ -1,7 +1,11 @@
 # 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/.
 
 [features/onboarding@mozilla.org] chrome.jar:
 % resource onboarding %content/
   content/ (content/*)
+  # Package UITour-lib.js in here rather than under
+  # /browser/components/uitour to avoid "unreferenced files" error when
+  # Onboarding extension is not built.
+  content/lib/UITour-lib.js (/browser/components/uitour/UITour-lib.js)