diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index 73c10aef1f..82269b4a05 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -30,11 +30,14 @@ File.helpers = [
   "has-own",
   "slice",
   "define-property",
-  "async-to-generator"
+  "async-to-generator",
+  "interop-require-wildcard",
+  "typeof"
 ];
 
 File.excludeHelpersFromRuntime = [
-  "async-to-generator"
+  "async-to-generator",
+  "typeof"
 ];
 
 File.normaliseOptions = function (opts) {