diff --git a/chrome/content/zotero/overlay.js b/chrome/content/zotero/overlay.js
deleted file mode 100644
index 5c0540a18d..0000000000
--- a/chrome/content/zotero/overlay.js
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
-    ***** BEGIN LICENSE BLOCK *****
-    
-    Copyright © 2009 Center for History and New Media
-                     George Mason University, Fairfax, Virginia, USA
-                     http://zotero.org
-    
-    This file is part of Zotero.
-    
-    Zotero is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-    
-    Zotero is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Affero General Public License for more details.
-    
-    You should have received a copy of the GNU Affero General Public License
-    along with Zotero.  If not, see <http://www.gnu.org/licenses/>.
-    
-    ***** END LICENSE BLOCK *****
-*/
-
-var ZoteroOverlay = new function () {
-	this.onLoad = async function () {
-		try {
-			if (!Zotero) {
-				throw new Error("No Zotero object");
-			}
-			if (Zotero.skipLoading) {
-				throw new Error("Skipping loading");
-			}
-			
-			await Zotero.Promise.all([Zotero.initializationPromise, Zotero.unlockPromise]);
-			
-			Zotero.debug("Initializing overlay");
-			
-			if (Zotero.skipLoading) {
-				throw new Error("Skipping loading");
-			}
-			
-			// Keep in sync with standalone.xul
-			if (Zotero.test) {
-				let ns = 'http://www.w3.org/1999/xhtml';
-				let div = document.createElementNS(ns, 'div');
-				let beforeNode = document.getElementById('browser');
-				div.id = 'tab-bar-container';
-				beforeNode.parentNode.insertBefore(div, beforeNode);
-			}
-			
-			ZoteroPane.init();
-		}
-		catch (e) {
-			Zotero.debug(e, 1);
-			throw e;
-		}
-	};
-	
-	
-	this.onUnload = function() {
-		ZoteroPane.destroy();
-	}
-}
-
-window.addEventListener("load", async function(e) {
-	try {
-		await ZoteroOverlay.onLoad(e);
-		await ZoteroPane.makeVisible();
-	}
-	catch (e) {
-		Components.utils.reportError(e);
-		if (Zotero) {
-			Zotero.debug(e, 1);
-		}
-		else {
-			dump(e + "\n\n");
-		}
-	}
-}, false);
-window.addEventListener("unload", function(e) { ZoteroOverlay.onUnload(e); }, false);