diff --git a/lib/fs/mock.js b/lib/fs/mock.js
index 2149e1d6b..784c5333a 100644
--- a/lib/fs/mock.js
+++ b/lib/fs/mock.js
@@ -16,7 +16,7 @@ function createMockFS(files) {
     var mtime = new Date();
 
     function getFile(filePath) {
-        var parts = path.normalize(filePath).split('/');
+        var parts = path.normalize(filePath).split(path.sep);
         return parts.reduce(function(list, part, i) {
             if (!list) return null;