diff --git a/lib/module.js b/lib/module.js
index 564f6c49d6cb..afbcd125f4a4 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -159,7 +159,8 @@ Module._findPath = function(request, paths) {
 
   var trailingSlash = (request.slice(-1) === '/');
 
-  var cacheKey = JSON.stringify({request: request, paths: paths});
+  var cacheKey = JSON.stringify({ request: path.normalize(request),
+    paths: paths});
   if (Module._pathCache[cacheKey]) {
     return Module._pathCache[cacheKey];
   }