diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index b940682797..2fcb5012ec 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -74,7 +74,6 @@ File.prototype.transform = function (ast) {
   this.ast = ast;
 
   var self = this;
-  var opts = this.opts;
 
   _.each(transform.transformers, function (transformer) {
     transformer.transform(self);
@@ -88,6 +87,13 @@ File.prototype.transform = function (ast) {
     ]));
   });
 
+  return this.generate();
+};
+
+File.prototype.generate = function () {
+  var opts = this.opts;
+  var ast  = this.ast;
+
   var result = util.generate(ast, opts);
 
   if (this.shebang) {