diff --git a/src/CustomElements.js b/src/CustomElements.js
index 69276fd..a0aa247 100644
--- a/src/CustomElements.js
+++ b/src/CustomElements.js
@@ -30,19 +30,6 @@ var hasNative = Boolean(document.registerElement);
 // other key related web components features.
 var useNative = !flags.register && hasNative && !window.ShadowDOMPolyfill && (!window.HTMLImports || HTMLImports.useNative);
 
-if (useNative) {
-  // FF doesn't store methods and properties after cloning
-  document.registerElement('check-cloning-element', {
-    prototype: Object.create(HTMLElement.prototype, {
-      test: { get: function() { return 1; } }
-    })
-  });
-
-  if (!document.createElement('check-cloning-element').cloneNode(true).test) {
-    useNative = false;
-  }
-}
-
 if (useNative) {
 
   // stub