diff --git a/lib/6to5/transform.js b/lib/6to5/transform.js
index f99837c1d2..937f37adc0 100644
--- a/lib/6to5/transform.js
+++ b/lib/6to5/transform.js
@@ -1,8 +1,8 @@
-var escodegen = require("escodegen");
-var traverse  = require("./traverse");
-var assert    = require("assert");
-var util      = require("./util");
-var _         = require("lodash");
+var traverse = require("./traverse");
+var assert   = require("assert");
+var path     = require("path");
+var util     = require("./util");
+var _        = require("lodash");
 
 var transform = module.exports = function (code, opts) {
   opts = opts || {};
@@ -20,7 +20,7 @@ var transform = module.exports = function (code, opts) {
 
   return util.parse(opts.filename, code, function (tree) {
     return transform._run(code, tree, opts);
-  }, true);
+  });
 };
 
 transform._run = function (code, tree, opts) {
@@ -43,23 +43,18 @@ transform._run = function (code, tree, opts) {
   });
 
   var genOpts = {
-    comment: true,
-    format: _.merge(opts.format, {
-      indent: {
-        style: "  "
-      }
-    })
+    format: opts.format
   };
 
   if (opts.sourceMap) {
-    genOpts.sourceMap = true;
+    genOpts.sourceMap = path.basename(opts.filename);
     genOpts.sourceContent = code;
     genOpts.sourceMapWithCode = true;
   }
 
-  var result = escodegen.generate(tree, genOpts);
+  var result = util.generate(tree, genOpts);
 
-  if (genOpts.sourceMapWithCode) {
+  if (opts.sourceMap) {
     if (opts.sourceMapObject) {
       return result;
     } else {
@@ -82,19 +77,18 @@ transform._runTransformer = function (transformer, tree, opts, generateUid) {
 };
 
 transform.test = function (actual, expect, opts, debug) {
-
   opts = opts || {};
   _.defaults(opts, { filename: "test" });
 
   var actualCode = actual.code.trim();
   var transformedCode = transform(actualCode, opts);
   var actualAst = util.parse(actual.filename, transformedCode);
+  actualCode = util.generate(actualAst);
 
   var expectCode = expect.code.trim();
   var expectAst = util.parse(expect.filename, expectCode);
+  expectCode = util.generate(expectAst);
 
-  actualCode = escodegen.generate(actualAst);
-  expectCode = escodegen.generate(expectAst);
   assert.equal(actualCode, expectCode);
 };
 
diff --git a/lib/6to5/util.js b/lib/6to5/util.js
index 11164e769e..9f007d06f7 100644
--- a/lib/6to5/util.js
+++ b/lib/6to5/util.js
@@ -1,4 +1,5 @@
 var estraverse = require("estraverse");
+var escodegen  = require("escodegen");
 var traverse   = require("./traverse");
 var esprima    = require("esprima");
 var path       = require("path");
@@ -10,23 +11,17 @@ _.each(esprima.Syntax, function (name) {
   estraverse.VisitorKeys[name] = estraverse.VisitorKeys[name] || [];
 });
 
-exports.parse = function (filename, code, callback, opts) {
-  opts = opts || {};
-  if (opts === true) {
-    opts =  {
+exports.parse = function (filename, code, callback) {
+  try {
+    var ast = esprima.parse(code, {
       comment: true,
+      source:  filename,
       tokens:  true,
       range:   true,
       loc:     true
-    };
-  }
+    });
 
-  try {
-    var ast = esprima.parse(code, opts);
-
-    if (ast.tokens && ast.comments) {
-      estraverse.attachComments(ast, ast.comments, ast.tokens);
-    }
+    estraverse.attachComments(ast, ast.comments, ast.tokens);
 
     if (callback) {
       return callback(ast);
@@ -43,6 +38,34 @@ exports.parse = function (filename, code, callback, opts) {
   }
 };
 
+exports.generate = function (ast, opts) {
+  opts = opts || {};
+
+  opts = _.merge({
+    comment: true,
+    format: {
+      indent: {
+        style: "  "
+      }
+    }
+  }, opts);
+
+  return escodegen.generate(ast, opts);
+};
+
+exports.removeProperties = function (tree) {
+  var clear = function (node) {
+    delete node.tokens;
+    delete node.range;
+    delete node.loc;
+  };
+
+  clear(tree);
+  traverse(tree, clear);
+
+  return tree;
+};
+
 exports.errorWithNode = function (node, msg) {
   var line = node.loc.start.line;
   var col  = node.loc.start.column;
@@ -190,6 +213,6 @@ if (fs.existsSync(templatesCacheLoc)) {
     var loc  = templatesLoc + "/" + name;
     var code = fs.readFileSync(loc, "utf8");
 
-    exports.templates[key] = exports.parse(loc, code);
+    exports.templates[key] = exports.removeProperties(exports.parse(loc, code));
   });
 }
diff --git a/package.json b/package.json
index 880ae49cc6..4ce4ad97bf 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into vanilla ES5 with no runtime required",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "repository": {
     "type": "git",
     "url": "https://github.com/sebmck/6to5.git"
diff --git a/test/fixtures/source-maps/basic/expected.js b/test/fixtures/source-maps/basic/expected.js
index d611f63bf6..a1e72c8e4b 100644
--- a/test/fixtures/source-maps/basic/expected.js
+++ b/test/fixtures/source-maps/basic/expected.js
@@ -13,4 +13,4 @@ var Test = function() {
 
   return Test;
 }();
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoibWFwLmpzb24iLCJzb3VyY2VzIjpbIi9Vc2Vycy9zZWJhc3RpYW4vUHJvamVjdHMvNnRvNS90ZXN0L2ZpeHR1cmVzL3NvdXJjZS1tYXBzL2Jhc2ljL2FjdHVhbC5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiSUFBTSxDQUFDLENBQUMsQ0FBQztXQUFILENBQUMsQ0FBQyxDQUFDLElBQ087O0VBRWQ7OzBCQUhJLENBQUMsQ0FBQyxDQUFDOztzQkFLRzs7TUFFVjs7OztTQVBJLENBQUMsQ0FBQyxDQUFDIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG4gIGNvbnN0cnVjdG9yKCkge1xuXG4gIH1cblxuICBnZXQgYmFyKCkge1xuXG4gIH1cbn0iXX0=
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImFjdHVhbC5qcyJdLCJuYW1lcyI6WyJUZXN0Il0sIm1hcHBpbmdzIjoiSUFBTUEsSTtXQUFBQSxJLEdBQ1U7QUFBQSxHOzBCQURWQSxJOztXQUtNO0FBQUEsTzs7O1NBTE5BLEkiLCJzb3VyY2VzQ29udGVudCI6WyJjbGFzcyBUZXN0IHtcbiAgY29uc3RydWN0b3IoKSB7XG5cbiAgfVxuXG4gIGdldCBiYXIoKSB7XG5cbiAgfVxufSJdfQ==