diff --git a/test/unit/dom-if.html b/test/unit/dom-if.html
index 8d5b71f7ad..38096e2cde 100644
--- a/test/unit/dom-if.html
+++ b/test/unit/dom-if.html
@@ -748,7 +748,7 @@
       assert.equal(el.parentNode, removalContainer);
       let div = document.createElement('div');
       document.body.appendChild(div);
-      let frag = div.createShadowRoot();
+      let frag = div.attachShadow({mode: 'open'});
       frag.appendChild(toBeRemoved);
       setTimeout(function() {
         assert.equal(el.parentNode, frag);