diff --git a/javascript/tree/tree.js b/javascript/tree/tree.js
index d2813b10e..c945bd29b 100644
--- a/javascript/tree/tree.js
+++ b/javascript/tree/tree.js
@@ -143,6 +143,8 @@ Tree.prototype = {
 	 * If 'before' is specified, then it will be inserted before that.
 	 */
 	appendTreeNode : function(child, before) {
+		if(!child) return;
+
 		// Remove from the old parent node - this will ensure that the classes of the old tree
 		// item are updated accordingly
 		if(child && child.parentTreeNode) {