diff --git a/src/CustomElements.js b/src/CustomElements.js
index a45ee7d..f75c581 100644
--- a/src/CustomElements.js
+++ b/src/CustomElements.js
@@ -25,14 +25,11 @@ var flags = scope.flags;
 
 // native document.register?
 
-var hasNative = Boolean(document.webkitRegister || document.register);
+var hasNative = Boolean(document.register);
 var useNative = !flags.register && hasNative;
 
 if (useNative) {
 
-  // normalize
-  document.register = document.register || document.webkitRegister;
-
   // stub
   var nop = function() {};