diff --git a/lib/index.js b/lib/index.js
index <HASH>..<HASH> 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -109,7 +109,7 @@ Server.prototype.serveClient = function(v){
     return require.resolve(file);
   };
   if (v && !clientSource) {
-    clientSource = read(resolvePath( 'socket.io-client/dist/socket.io.min.js'), 'utf-8');
+    clientSource = read(resolvePath( 'socket.io-client/dist/socket.io.js'), 'utf-8');
     try {
       clientSourceMap = read(resolvePath( 'socket.io-client/dist/socket.io.js.map'), 'utf-8');
     } catch(err) {
@@ -323,7 +323,6 @@ Server.prototype.serve = function(req, res){
   debug('serve client source');
   res.setHeader('Content-Type', 'application/javascript');
   res.setHeader('ETag', expectedEtag);
-  res.setHeader('X-SourceMap', 'socket.io.js.map');
   res.writeHead(200);
   res.end(clientSource);
 };
[fix] Update path of client file (#<I>)