diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index 2e2abc6c5..10701314a 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -1435,6 +1435,13 @@ Components.utils.import("resource://gre/modules/osfile.jsm");
 		Object.defineProperty(obj, prop, d);
 	}
 	
+	this.extendClass = function(superClass, newClass) {
+		newClass._super = superClass;
+		newClass.prototype = Object.create(superClass.prototype);
+		newClass.prototype.constructor = newClass;
+	}
+	
+	
 	/*
 	 * This function should be removed
 	 *
@@ -1620,46 +1627,6 @@ Components.utils.import("resource://gre/modules/osfile.jsm");
 	}
 	
 	
-	/**
-	 * Defines property on the object
-	 * More compact way to do Object.defineProperty
-	 *
-	 * @param {Object} obj Target object
-	 * @param {String} prop Property to be defined
-	 * @param {Object} desc Propery descriptor. If not overriden, "enumerable" is true
-	 * @param {Object} opts Options:
-	 *   lateInit {Boolean} If true, the _getter_ is intended for late
-	 *     initialization of the property. The getter is replaced with a simple
-	 *     property once initialized.
-	 */
-	this.defineProperty = function(obj, prop, desc, opts) {
-		if (typeof prop != 'string') throw new Error("Property must be a string");
-		var d = { __proto__: null, enumerable: true, configurable: true }; // Enumerable by default
-		for (let p in desc) {
-			if (!desc.hasOwnProperty(p)) continue;
-			d[p] = desc[p];
-		}
-		
-		if (opts) {
-			if (opts.lateInit && d.get) {
-				let getter = d.get;
-				d.get = function() {
-					var val = getter.call(this);
-					this[prop] = val; // Replace getter with value
-					return val;
-				}
-			}
-		}
-		
-		Object.defineProperty(obj, prop, d);
-	}
-	
-	this.extendClass = function(superClass, newClass) {
-		newClass._super = superClass;
-		newClass.prototype = Object.create(superClass.prototype);
-		newClass.prototype.constructor = newClass;
-	}
-	
 	/**
 	 * Allow other events (e.g., UI updates) on main thread to be processed if necessary
 	 *