diff --git a/content/docs/web-components.md b/content/docs/web-components.md
index d29453a8..c3d418b6 100644
--- a/content/docs/web-components.md
+++ b/content/docs/web-components.md
@@ -54,3 +54,7 @@ class XSearch extends HTMLElement {
 }
 customElements.define('x-search', XSearch);
 ```
+
+>Note:
+>
+>This code **will not** work if you transform classes with Babel. See [this issue](https://github.com/w3c/webcomponents/issues/587) for the discussion.