diff --git a/test/unit/disable-upgrade.html b/test/unit/disable-upgrade.html
index 14dd626de4..4a709e1fb0 100644
--- a/test/unit/disable-upgrade.html
+++ b/test/unit/disable-upgrade.html
@@ -185,9 +185,10 @@ <h2 id="element">[[prop]]</h2>
 suite('disable-upgrade', function() {
   let el;
 
-  setup(() => {
+  setup((done) => {
     el = document.createElement('my-element');
     document.body.appendChild(el);
+    window.addEventListener('DOMContentLoaded', function() { done(); });
   });
   teardown(function() {
     document.body.removeChild(el);