diff --git a/src/dev/index.js b/src/dev/index.js
index 0417d48..013f42f 100644
--- a/src/dev/index.js
+++ b/src/dev/index.js
@@ -39,7 +39,13 @@ module.exports = {
       }
     }
 
+    const observedAttributes = app.type.observedAttributes;
+
     const proto = class extends HTMLElement {
+      static get observedAttributes() {
+        return observedAttributes || [];
+      }
+
       connectedCallback() {
         const webComponentInstance = this;
         let mountPoint = webComponentInstance;