diff --git a/chrome/content/zotero/xpcom/data/dataObject.js b/chrome/content/zotero/xpcom/data/dataObject.js
index a7a9b7ce5..8452e9e0a 100644
--- a/chrome/content/zotero/xpcom/data/dataObject.js
+++ b/chrome/content/zotero/xpcom/data/dataObject.js
@@ -55,17 +55,17 @@ Zotero.DataObject = function () {
 Zotero.DataObject.prototype._objectType = 'dataObject';
 Zotero.DataObject.prototype._dataTypes = [];
 
-Zotero.Utilities.Internal.defineProperty(Zotero.DataObject.prototype, 'objectType', {
+Zotero.defineProperty(Zotero.DataObject.prototype, 'objectType', {
 	get: function() this._objectType
 });
-Zotero.Utilities.Internal.defineProperty(Zotero.DataObject.prototype, 'libraryKey', {
+Zotero.defineProperty(Zotero.DataObject.prototype, 'libraryKey', {
 	get: function() this._libraryID + "/" + this._key
 });
-Zotero.Utilities.Internal.defineProperty(Zotero.DataObject.prototype, 'parentKey', {
+Zotero.defineProperty(Zotero.DataObject.prototype, 'parentKey', {
 	get: function() this._parentKey,
 	set: function(v) this._setParentKey(v)
 });
-Zotero.Utilities.Internal.defineProperty(Zotero.DataObject.prototype, 'parentID', {
+Zotero.defineProperty(Zotero.DataObject.prototype, 'parentID', {
 	get: function() this._getParentID(),
 	set: function(v) this._setParentID(v)
 });
diff --git a/chrome/content/zotero/xpcom/data/libraries.js b/chrome/content/zotero/xpcom/data/libraries.js
index 8234f2083..828e35af7 100644
--- a/chrome/content/zotero/xpcom/data/libraries.js
+++ b/chrome/content/zotero/xpcom/data/libraries.js
@@ -28,7 +28,7 @@ Zotero.Libraries = new function () {
 		_userLibraryID,
 		_libraryDataLoaded = false;
 	
-	Zotero.Utilities.Internal.defineProperty(this, 'userLibraryID', {
+	Zotero.defineProperty(this, 'userLibraryID', {
 		get: function() { 
 			if (!_libraryDataLoaded) {
 				throw new Error("Library data not yet loaded");
diff --git a/chrome/content/zotero/xpcom/utilities_internal.js b/chrome/content/zotero/xpcom/utilities_internal.js
index f88c08f75..bbe1767c0 100644
--- a/chrome/content/zotero/xpcom/utilities_internal.js
+++ b/chrome/content/zotero/xpcom/utilities_internal.js
@@ -493,24 +493,6 @@ Zotero.Utilities.Internal = {
 		}, 0, 0, null);
 		
 		return pipe.inputStream;
-	},
-	
-	/**
-	 * 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
-	 */
-	"defineProperty": function(obj, prop, desc) {
-		if (typeof prop != 'string') throw new Error("Property must be a string");
-		var d = { __proto__: null, enumerable: true }; // Enumerable by default
-		for (let p in desc) {
-			if (!desc.hasOwnProperty(p)) continue;
-			d[p] = desc[p];
-		}
-		Object.defineProperty(obj, prop, d);
 	}
 }
 
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index cdd4bd080..0db278232 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -1400,6 +1400,24 @@ 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
+	 */
+	this.defineProperty = function(obj, prop, desc) {
+		if (typeof prop != 'string') throw new Error("Property must be a string");
+		var d = { __proto__: null, enumerable: true }; // Enumerable by default
+		for (let p in desc) {
+			if (!desc.hasOwnProperty(p)) continue;
+			d[p] = desc[p];
+		}
+		Object.defineProperty(obj, prop, d);
+	}
+	
 	/*
 	 * This function should be removed
 	 *