diff --git a/bin/6to5-node b/bin/6to5-node
index c55ff4eda0..c79ce0e17d 100755
--- a/bin/6to5-node
+++ b/bin/6to5-node
@@ -41,9 +41,7 @@ var _eval = function (code, filename) {
 };
 
 if (commander.eval) {
-  var code = to5.transform(commander.eval, { filename: "eval" }).code;
-
-  var result = _eval(code, "eval");
+  var result = _eval(commander.eval, "eval");
   if (commander.print) console.log(result);
 } else {
   var filenames = commander.args;
diff --git a/bin/6to5/dir.js b/bin/6to5/dir.js
index 90860077f0..9854f33472 100644
--- a/bin/6to5/dir.js
+++ b/bin/6to5/dir.js
@@ -13,7 +13,7 @@ module.exports = function (commander, filenames, opts) {
   var write = function (src, relative) {
     var dest = path.join(commander.outDir, relative);
 
-    var data = util.compile(src, dest);
+    var data = util.compile(src, { sourceMapName: dest });
 
     var up = path.normalize(dest + "/..");
     mkdirp.sync(up);
diff --git a/bin/6to5/file.js b/bin/6to5/file.js
index 34a6e796ea..1afc7587a2 100644
--- a/bin/6to5/file.js
+++ b/bin/6to5/file.js
@@ -100,8 +100,8 @@ module.exports = function (commander, filenames, opts) {
       }
     });
 
-    _.each(_filenames, function (filename) {
-      results.push(util.compile(filename));
+    _.each(_filenames, function (filename, i) {
+      results.push(util.compile(filename, { _noStrict: i != 0 }));
     });
 
     output();
diff --git a/bin/6to5/util.js b/bin/6to5/util.js
index ccec63ee7d..367f6326c3 100644
--- a/bin/6to5/util.js
+++ b/bin/6to5/util.js
@@ -9,9 +9,9 @@ exports.readdirFilter = function (filename) {
   return readdir(filename).filter(util.canCompile);
 };
 
-exports.transform = function (filename, code, to) {
-  var opts = _.extend({ filename: filename }, index.opts);
-  if (to) opts.sourceMapName = to;
+exports.transform = function (filename, code, opts) {
+  opts = _.extend(opts || {}, index.opts);
+  opts.filename = filename;
 
   var result = to5.transform(code, opts);
   result.filename = filename;
@@ -19,7 +19,7 @@ exports.transform = function (filename, code, to) {
   return result;
 };
 
-exports.compile = function (filename, to) {
+exports.compile = function (filename, opts) {
   var code = fs.readFileSync(filename, "utf8");
-  return exports.transform(filename, code, to);
+  return exports.transform(filename, code, opts);
 };