diff --git a/content/treestyletab/treestyletab.xul b/content/treestyletab/treestyletab.xul
index e0bee6ce..4dafd284 100644
--- a/content/treestyletab/treestyletab.xul
+++ b/content/treestyletab/treestyletab.xul
@@ -16,7 +16,6 @@
 
 <script src="res/stopRendering.js" type="application/javascript"/>
 <script src="res/tabsDragUtils.js" type="application/javascript"/>
-<script src="res/UninstallationListener.js" type="application/javascript"/>
 <script src="treestyletab.js" type="application/javascript"/>
 <script src="windowHelper.js" type="application/javascript"/>
 <script src="windowHelperHacks.js" type="application/javascript"/>
diff --git a/content/treestyletab/res/UninstallationListener.js b/modules/lib/UninstallationListener.js
similarity index 83%
rename from content/treestyletab/res/UninstallationListener.js
rename to modules/lib/UninstallationListener.js
index 92fceafa..c8fb7959 100644
--- a/content/treestyletab/res/UninstallationListener.js
+++ b/modules/lib/UninstallationListener.js
@@ -13,6 +13,24 @@
  original:
    http://github.com/piroor/fxaddonlibs/blob/master/UninstallationListener.js
 */
+
+/* To work as a JS Code Module  */
+if (typeof window == 'undefined' ||
+	(window && typeof window.constructor == 'function')) {
+	this.EXPORTED_SYMBOLS = ['UninstallationListener'];
+
+	// If namespace.jsm is available, export symbols to the shared namespace.
+	// See: http://github.com/piroor/fxaddonlibs/blob/master/namespace.jsm
+	try {
+		let ns = {};
+		Components.utils.import('resource://my-modules/namespace.jsm', ns);
+		/* var */ window = ns.getNamespaceFor('piro.sakura.ne.jp');
+	}
+	catch(e) {
+		window = {};
+	}
+}
+
 (function() {
 	const currentRevision = 2;
 
@@ -165,3 +183,7 @@
 		}
 	};
 })();
+
+if (window != this) { // work as a JS Code Module
+	this.UninstallationListener = window['piro.sakura.ne.jp'].UninstallationListener;
+}
diff --git a/modules/window.js b/modules/window.js
index b7af1115..d6c48627 100644
--- a/modules/window.js
+++ b/modules/window.js
@@ -42,6 +42,9 @@ Components.utils.import('resource://gre/modules/XPCOMUtils.jsm');
 
 XPCOMUtils.defineLazyModuleGetter(this, "prefs",
   'resource://treestyletab-modules/lib/prefs.js');
+XPCOMUtils.defineLazyModuleGetter(this, 'UninstallationListener',
+  'resource://treestyletab-modules/lib/UninstallationListener.js');
+
 XPCOMUtils.defineLazyModuleGetter(this, "Services", "resource://gre/modules/Services.jsm");
 
 Components.utils.import('resource://treestyletab-modules/base.js');
@@ -410,7 +413,7 @@ TreeStyleTabWindow.prototype = {
 					prefs.clearPref(pref+'.backup');
 				}
 			}.bind(this);
-		new this.window['piro.sakura.ne.jp'].UninstallationListener({
+		new UninstallationListener({
 			id : 'treestyletab@piro.sakura.ne.jp',
 			onuninstalled : restorePrefs,
 			ondisabled : restorePrefs