diff --git a/demo.html b/demo.html
index cb9d7ff..41eb21f 100644
--- a/demo.html
+++ b/demo.html
@@ -35,7 +35,10 @@ <h1>WOW.js</h1>
     wow = new WOW(
       {
         animateClass: 'animated',
-        offset:       100
+        offset:       100,
+        callback:     function(box) {
+          console.log("WOW: animating <" + box.tagName.toLowerCase() + ">")
+        }
       }
     );
     wow.init();