diff --git a/lib/request.js b/lib/request.js
index 372a9915e96..ee3fb961cd0 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -249,22 +249,13 @@ defineGetter(req, 'query', function query(){
  *      req.is('html');
  *      // => false
  *
- * @param {String|Array} types...
- * @return {String|false|null}
+ * @param {(String|Array)} types...
+ * @return {(String|false|null)}
  * @public
  */
 
 req.is = function is(types) {
-  var arr = types;
-
-  // support flattened arguments
-  if (!Array.isArray(types)) {
-    arr = new Array(arguments.length);
-    for (var i = 0; i < arr.length; i++) {
-      arr[i] = arguments[i];
-    }
-  }
-
+  const arr = Array.isArray(types) ? types : Array.from(arguments);
   return typeis(this, arr);
 };