diff --git a/hacks.md b/hacks.md
index 1d11f03..6548c7d 100644
--- a/hacks.md
+++ b/hacks.md
@@ -26,3 +26,5 @@ new Vivus('mySVG', {}, function (obj) {
   obj.el.classList.add('finished');
 });
 ```
+
+**WARNING**: This hack cannot work on sandboxed solutions like the use of `object` tag.