diff --git a/chrome/content/zotero/standalone/hiddenWindow.xul b/chrome/content/zotero/standalone/hiddenWindow.xul
index ddf43400f6..45ec203010 100644
--- a/chrome/content/zotero/standalone/hiddenWindow.xul
+++ b/chrome/content/zotero/standalone/hiddenWindow.xul
@@ -39,6 +39,7 @@
 <window id="main-window" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 	<script type="application/javascript" src="chrome://global/content/globalOverlay.js"/>
 	<script>
+		// Equivalent to Zotero.openMainWindow()
 		function openMainWindow() {
 			var prefService = Components.classes["@mozilla.org/preferences-service;1"]
 				.getService(Components.interfaces.nsIPrefBranch);
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index 1c0cf0937b..750e430af6 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -1061,6 +1061,17 @@ Services.scriptloader.loadSubScript("resource://zotero/polyfill.js");
 	}
 	
 	
+	this.openMainWindow = function () {
+		var prefService = Components.classes["@mozilla.org/preferences-service;1"]
+			.getService(Components.interfaces.nsIPrefBranch);
+		var chromeURI = prefService.getCharPref('toolkit.defaultChromeURI');
+		var flags = prefService.getCharPref("toolkit.defaultChromeFeatures", "chrome,dialog=no,all");
+		var ww = Components.classes['@mozilla.org/embedcomp/window-watcher;1']
+			.getService(Components.interfaces.nsIWindowWatcher);
+		return ww.openWindow(null, chromeURI, '_blank', flags, null);
+	}
+	
+	
 	/**
 	 * Launch a file, the best way we can
 	 */