diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 0080148f7..bd13b32b3 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -2032,6 +2032,8 @@ Zotero.Item.prototype.save = function() {
 		Zotero.Notifier.trigger('modify', 'item', this.id, { old: this._previousData });
 	}
 	
+	this._previousData = null;
+	
 	if (isNew) {
 		var id = this.id;
 		this._disabled = true;