diff --git a/test/smoke/simulate-import.html b/test/smoke/simulate-import.html
new file mode 100644
index 0000000000..a0c4164179
--- /dev/null
+++ b/test/smoke/simulate-import.html
@@ -0,0 +1,54 @@
+<!doctype html>
+<!--
+@license
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<html>
+<head>
+  <title>simulate imports</title>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+</head>
+<body>
+  <script>
+    class MyElement extends HTMLElement {
+      constructor() {
+        super();
+        console.log(this.localName, 'is a custom element!')
+      }
+    }
+    customElements.define('my-element', MyElement);
+
+    var holdingPen = document.createElement('div');
+    function customizedDomFromHTMLString(htmlString) {
+      holdingPen.innerHTML = htmlString;
+      var frag = document.createDocumentFragment();
+      while (holdingPen.firstChild) {
+        frag.appendChild(holdingPen.firstChild);
+      }
+      return frag;
+    }
+
+    var importedString = '<my-element></my-element><my-upgrade></my-upgrade>';
+
+    var doc = document.implementation.createHTMLDocument();
+    doc.body.appendChild(customizedDomFromHTMLString(importedString));
+
+
+    class MyUpgrade extends HTMLElement {
+      constructor() {
+        super();
+        console.log(this.localName, 'is a custom element!')
+      }
+    }
+    customElements.define('my-upgrade', MyUpgrade);
+  </script>
+
+</body>
+</html>
