diff --git a/simpleCart.js b/simpleCart.js
index cfeeb0b..8a13fe6 100755
--- a/simpleCart.js
+++ b/simpleCart.js
@@ -202,7 +202,7 @@
 
 					if (!quiet) {
 						// trigger after add event
-						simpleCart.trigger('afterAdd', [newItem, isUndefined(oldItem)]);
+						simpleCart.trigger('afterAdd', [newItem, oldItem == false]);
 					}
 
 					// return a reference to the added item