diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 136c85631..4ea868c33 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -781,7 +781,7 @@ Zotero.Item.prototype.setField = function(field, value, loadIn) {
 	
 	let itemTypeID = this.itemTypeID;
 	if (!itemTypeID) {
-		throw ('Item type must be set before setting field data');
+		throw new Error('Item type must be set before setting field data');
 	}
 	
 	var fieldID = Zotero.ItemFields.getID(field);
@@ -1173,7 +1173,10 @@ Zotero.Item.prototype._saveData = Zotero.Promise.coroutine(function* (env) {
 	var options = env.options;
 	
 	var itemTypeID = this.itemTypeID;
-		
+	if (!itemTypeID) {
+		throw new Error("Item type must be set before saving");
+	}
+	
 	var sqlColumns = [];
 	var sqlValues = [];
 	var reloadParentChildItems = {};
diff --git a/test/tests/itemTest.js b/test/tests/itemTest.js
index 19fa7bbeb..e65979278 100644
--- a/test/tests/itemTest.js
+++ b/test/tests/itemTest.js
@@ -19,6 +19,11 @@ describe("Zotero.Item", function () {
 	});
 	
 	describe("#setField", function () {
+		it("should throw an error if item type isn't set", function* () {
+			var item = new Zotero.Item;
+			assert.throws(item.setField.bind(item, 'title', 'test'), "Item type must be set before setting field data");
+		})
+		
 		it("should mark a field as changed", function () {
 			var item = new Zotero.Item('book');
 			item.setField('title', 'Foo');