diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 2abc9cdf7..a0307e74e 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -590,7 +590,7 @@ Zotero.Item.prototype.setType = function(itemTypeID, loadIn) {
 	if (loadIn) {
 		this._itemDataLoaded = false;
 	}
-	else {
+	else if(oldItemTypeID) {
 		this._markFieldChange('itemType', Zotero.ItemTypes.getName(oldItemTypeID));
 		if (!this._changedPrimaryData) {
 			this._changedPrimaryData = {};