diff --git a/lib/babel/transformation/file.js b/lib/babel/transformation/file.js
index c98dd022e3..348c5c37bd 100644
--- a/lib/babel/transformation/file.js
+++ b/lib/babel/transformation/file.js
@@ -13,6 +13,7 @@ var includes           = require("lodash/collection/includes");
 var clone              = require("../helpers/clone");
 var parse              = require("../helpers/parse");
 var Scope              = require("../traversal/scope");
+var slash              = require("slash");
 var util               = require("../util");
 var path               = require("path");
 var each               = require("lodash/collection/each");
@@ -128,9 +129,9 @@ File.prototype.normalizeOptions = function (opts) {
   });
 
   // normalize windows path separators to unix
-  opts.filename = util.normalisePathSeparator(opts.filename);
+  opts.filename = slash(opts.filename);
   if (opts.sourceRoot) {
-    opts.sourceRoot = util.normalisePathSeparator(opts.sourceRoot);
+    opts.sourceRoot = slash(opts.sourceRoot);
   }
 
   opts.basename = path.basename(opts.filename, path.extname(opts.filename));
diff --git a/lib/babel/util.js b/lib/babel/util.js
index 865192aea7..4b1b1e8ea3 100644
--- a/lib/babel/util.js
+++ b/lib/babel/util.js
@@ -29,10 +29,6 @@ exports.canCompile = function (filename, altExts) {
 
 exports.canCompile.EXTENSIONS = [".js", ".jsx", ".es6", ".es"];
 
-exports.normalisePathSeparator = function (filename) {
-  return filename.replace(/\\/g, "/");
-};
-
 exports.resolve = function (loc) {
   try {
     return require.resolve(loc);
diff --git a/package.json b/package.json
index b5580293a1..59e278bfd2 100644
--- a/package.json
+++ b/package.json
@@ -60,6 +60,7 @@
     "regenerator-babel": "0.8.10-2",
     "regexpu": "^1.1.1",
     "repeating": "^1.1.2",
+    "slash": "^1.0.0",
     "source-map": "^0.1.43",
     "source-map-support": "^0.2.9",
     "source-map-to-comment": "^1.0.0",