diff --git a/chrome/content/zotero/xpcom/api.js b/chrome/content/zotero/xpcom/api.js
index 39f5b5f39b..81229692f3 100644
--- a/chrome/content/zotero/xpcom/api.js
+++ b/chrome/content/zotero/xpcom/api.js
@@ -130,7 +130,7 @@ Zotero.API = {
 				// Filter results by item key
 				if (params.itemKey) {
 					ids = ids.filter(function (id) {
-						var [libraryID, key] = Zotero.Items.getLibraryAndKeyFromID(id);
+						var {libraryID, key} = Zotero.Items.getLibraryAndKeyFromID(id);
 						return params.itemKey.indexOf(key) !== -1;
 					});
 				}
diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index fe77a6cda1..f4d2d83196 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -50,7 +50,8 @@ Zotero.Attachments = new function(){
 			// Create a new attachment
 			var attachmentItem = new Zotero.Item('attachment');
 			if (parentItemID) {
-				let [parentLibraryID, parentKey] = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
+				let {libraryID: parentLibraryID, key: parentKey} =
+					Zotero.Items.getLibraryAndKeyFromID(parentItemID);
 				attachmentItem.libraryID = parentLibraryID;
 			}
 			else if (libraryID) {
@@ -151,7 +152,7 @@ Zotero.Attachments = new function(){
 		yield Zotero.DB.executeTransaction(function* () {
 			// Create a new attachment
 			var attachmentItem = new Zotero.Item('attachment');
-			let [libraryID, parentKey] = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
+			let {libraryID, key: parentKey} = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
 			attachmentItem.libraryID = libraryID;
 			attachmentItem.setField('title', title);
 			attachmentItem.setField('url', url);
@@ -318,7 +319,8 @@ Zotero.Attachments = new function(){
 					attachmentItem.libraryID = libraryID;
 				}
 				else if (parentItemID) {
-					let [parentLibraryID, parentKey] = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
+					let {libraryID: parentLibraryID, key: parentKey} =
+						Zotero.Items.getLibraryAndKeyFromID(parentItemID);
 					attachmentItem.libraryID = parentLibraryID;
 				}
 				attachmentItem.setField('title', title ? title : fileName);
@@ -627,7 +629,8 @@ Zotero.Attachments = new function(){
 				attachmentItem.libraryID = libraryID;
 			}
 			else if (parentItemID) {
-				let [parentLibraryID, parentKey] = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
+				let {libraryID: parentLibraryID, key: parentKey} =
+					Zotero.Items.getLibraryAndKeyFromID(parentItemID);
 				Zotero.debug('==-=');
 				Zotero.debug(parentItemID);
 				Zotero.debug(parentLibraryID);
@@ -862,7 +865,7 @@ Zotero.Attachments = new function(){
 		if (!itemID) {
 			throw new Error("itemID not provided");
 		}
-		var [libraryID, key] = Zotero.Items.getLibraryAndKeyFromID(itemID);
+		var {libraryID, key} = Zotero.Items.getLibraryAndKeyFromID(itemID);
 		if (!key) {
 			throw new Error("Item " + itemID + " not found");
 		}
@@ -1287,7 +1290,8 @@ Zotero.Attachments = new function(){
 		return Zotero.DB.executeTransaction(function* () {
 			var attachmentItem = new Zotero.Item('attachment');
 			if (parentItemID) {
-				let [parentLibraryID, parentKey] = Zotero.Items.getLibraryAndKeyFromID(parentItemID);
+				let {libraryID: parentLibraryID, key: parentKey} =
+					Zotero.Items.getLibraryAndKeyFromID(parentItemID);
 				if (parentLibraryID && linkMode == Zotero.Attachments.LINK_MODE_LINKED_FILE) {
 					throw new Error("Cannot save linked file in non-local library");
 				}
diff --git a/chrome/content/zotero/xpcom/data/dataObject.js b/chrome/content/zotero/xpcom/data/dataObject.js
index d2d74eec0e..802a2fdcd5 100644
--- a/chrome/content/zotero/xpcom/data/dataObject.js
+++ b/chrome/content/zotero/xpcom/data/dataObject.js
@@ -161,7 +161,7 @@ Zotero.DataObject.prototype._getParentID = function () {
 Zotero.DataObject.prototype._setParentID = function (id) {
 	return this._setParentKey(
 		id
-		? this.ObjectsClass.getLibraryAndKeyFromID(Zotero.DataObjectUtilities.checkDataID(id))[1]
+		? this.ObjectsClass.getLibraryAndKeyFromID(Zotero.DataObjectUtilities.checkDataID(id)).key
 		: null
 	);
 }
diff --git a/chrome/content/zotero/xpcom/data/dataObjects.js b/chrome/content/zotero/xpcom/data/dataObjects.js
index d2c71d7e7c..049a7e4677 100644
--- a/chrome/content/zotero/xpcom/data/dataObjects.js
+++ b/chrome/content/zotero/xpcom/data/dataObjects.js
@@ -270,10 +270,11 @@ Zotero.DataObjects.prototype.exists = function (itemID) {
 
 
 /**
- * @return {Array} Array with libraryID and key
+ * @return {Object} Object with 'libraryID' and 'key'
  */
 Zotero.DataObjects.prototype.getLibraryAndKeyFromID = function (id) {
-	return this._objectKeys[id] ? this._objectKeys[id] : false;
+	var lk = this._objectKeys[id];
+	return lk ? { libraryID: lk[0], key: lk[1] } : false;
 }
 
 
@@ -413,7 +414,7 @@ Zotero.DataObjects.prototype.unload = function () {
 	var ids = Zotero.flattenArguments(arguments);
 	for (var i=0; i<ids.length; i++) {
 		let id = ids[i];
-		let [libraryID, key] = this.getLibraryAndKeyFromID(id);
+		let {libraryID, key} = this.getLibraryAndKeyFromID(id);
 		if (key) {
 			delete this._objectIDs[libraryID][key];
 			delete this._objectKeys[id];
diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 8b93e12d7c..346dcf39cd 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -4103,7 +4103,7 @@ Zotero.Item.prototype.toJSON = Zotero.Promise.coroutine(function* (options, patc
 	// Collections
 	yield this.loadCollections();
 	obj.collections = this.getCollections().map(function (id) {
-		return this.ContainerObjectsClass.getLibraryAndKeyFromID(id)[1];
+		return this.ContainerObjectsClass.getLibraryAndKeyFromID(id).key;
 	}.bind(this));
 	
 	// Relations
diff --git a/chrome/content/zotero/xpcom/search.js b/chrome/content/zotero/xpcom/search.js
index 9fd531fe79..b6ce4ae7e6 100644
--- a/chrome/content/zotero/xpcom/search.js
+++ b/chrome/content/zotero/xpcom/search.js
@@ -347,7 +347,7 @@ Zotero.Search.prototype.addCondition = function (condition, operator, value, req
 	}
 	// Shortcut to add a collection (which must be loaded first)
 	else if (condition == 'collectionID') {
-		let [libraryID, key] = Zotero.Collections.getLibraryAndKeyFromID(value);
+		let {libraryID, key} = Zotero.Collections.getLibraryAndKeyFromID(value);
 		if (!key) {
 			let msg = "Collection " + value + " not found";
 			Zotero.debug(msg, 2);
@@ -362,7 +362,7 @@ Zotero.Search.prototype.addCondition = function (condition, operator, value, req
 	}
 	// Shortcut to add a saved search (which must be loaded first)
 	else if (condition == 'savedSearchID') {
-		let [libraryID, key] = Zotero.Searches.getLibraryAndKeyFromID(value);
+		let {libraryID, key} = Zotero.Searches.getLibraryAndKeyFromID(value);
 		if (!key) {
 			let msg = "Saved search " + value + " not found";
 			Zotero.debug(msg, 2);
diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index 3f03d1d604..7c9db45504 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -3126,7 +3126,7 @@ var ZoteroPane = new function()
 		var str = event.currentTarget.ownerDocument.popupNode.ownerDocument.defaultView.getSelection().toString();
 		var uri = event.currentTarget.ownerDocument.popupNode.ownerDocument.location.href;
 		var itemID = ZoteroPane.addItemFromPage();
-		var [libraryID, key] = Zotero.Items.getLibraryAndKeyFromID(itemID);
+		var {libraryID, key} = Zotero.Items.getLibraryAndKeyFromID(itemID);
 		ZoteroPane.newNote(false, key, str, uri)
 	};