diff --git a/src/main/java/com/github/nkzawa/socketio/client/Manager.java b/src/main/java/com/github/nkzawa/socketio/client/Manager.java
index dda72ac..218836d 100644
--- a/src/main/java/com/github/nkzawa/socketio/client/Manager.java
+++ b/src/main/java/com/github/nkzawa/socketio/client/Manager.java
@@ -66,6 +66,11 @@ public class Manager extends Emitter {
 
     public static final String EVENT_RECONNECTING = "reconnecting";
 
+    /**
+     * Called when a new transport is created. (experimental)
+     */
+    public static final String EVENT_TRANSPORT = Engine.EVENT_TRANSPORT;
+
     /*package*/ static SSLContext defaultSSLContext;
 
     /*package*/ ReadyState readyState = null;
@@ -221,6 +226,14 @@ public class Manager extends Emitter {
 
                 Manager.this.readyState = ReadyState.OPENING;
 
+                // propagate transport event.
+                socket.on(Engine.EVENT_TRANSPORT, new Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        self.emit(Manager.EVENT_TRANSPORT, args);
+                    }
+                });
+
                 final On.Handle openSub = On.on(socket, Engine.EVENT_OPEN, new Listener() {
                     @Override
                     public void call(Object... objects) {
diff --git a/src/test/java/com/github/nkzawa/socketio/client/ServerConnectionTest.java b/src/test/java/com/github/nkzawa/socketio/client/ServerConnectionTest.java
index 2ad8dcc..ae85e72 100644
--- a/src/test/java/com/github/nkzawa/socketio/client/ServerConnectionTest.java
+++ b/src/test/java/com/github/nkzawa/socketio/client/ServerConnectionTest.java
@@ -1,12 +1,16 @@
 package com.github.nkzawa.socketio.client;
 
 import com.github.nkzawa.emitter.Emitter;
+import com.github.nkzawa.engineio.client.Transport;
+import com.github.nkzawa.engineio.client.transports.Polling;
+import com.github.nkzawa.engineio.client.transports.WebSocket;
 import org.json.JSONObject;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 import java.net.URISyntaxException;
+import java.util.Map;
 import java.util.concurrent.Semaphore;
 
 import static org.hamcrest.CoreMatchers.*;
@@ -262,4 +266,72 @@ public class ServerConnectionTest extends Connection {
         socket.connect();
         semaphore.acquire();
     }
+
+    @Test(timeout = TIMEOUT)
+    public void pollingHeaders() throws URISyntaxException, InterruptedException {
+        final Semaphore semaphore = new Semaphore(0);
+
+        IO.Options opts = createOptions();
+        opts.transports = new String[] {Polling.NAME};
+        socket = client(opts);
+        socket.io().on(Manager.EVENT_TRANSPORT, new Emitter.Listener() {
+            @Override
+            public void call(Object... args) {
+                Transport transport = (Transport)args[0];
+                transport.on(Transport.EVENT_REQUEST_HEADERS, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        @SuppressWarnings("unchecked")
+                        Map<String, String> headers = (Map<String, String>)args[0];
+                        headers.put("X-SocketIO", "hi");
+                    }
+                }).on(Transport.EVENT_RESPONSE_HEADERS, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        @SuppressWarnings("unchecked")
+                        Map<String, String> headers = (Map<String, String>)args[0];
+                        assertThat(headers.get("X-SocketIO"), is("hi"));
+                        socket.close();
+                        semaphore.release();
+                    }
+                });
+            }
+        });
+        socket.open();
+        semaphore.acquire();
+    }
+
+    @Test(timeout = TIMEOUT)
+    public void websocketHandshakeHeaders() throws URISyntaxException, InterruptedException {
+        final Semaphore semaphore = new Semaphore(0);
+
+        IO.Options opts = createOptions();
+        opts.transports = new String[] {WebSocket.NAME};
+        socket = client(opts);
+        socket.io().on(Manager.EVENT_TRANSPORT, new Emitter.Listener() {
+            @Override
+            public void call(Object... args) {
+                Transport transport = (Transport)args[0];
+                transport.on(Transport.EVENT_REQUEST_HEADERS, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        @SuppressWarnings("unchecked")
+                        Map<String, String> headers = (Map<String, String>)args[0];
+                        headers.put("X-SocketIO", "hi");
+                    }
+                }).on(Transport.EVENT_RESPONSE_HEADERS, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        @SuppressWarnings("unchecked")
+                        Map<String, String> headers = (Map<String, String>)args[0];
+                        assertThat(headers.get("X-SocketIO"), is("hi"));
+                        socket.close();
+                        semaphore.release();
+                    }
+                });
+            }
+        });
+        socket.open();
+        semaphore.acquire();
+    }
 }
diff --git a/src/test/resources/server.js b/src/test/resources/server.js
index 4414c4a..06a7ce4 100644
--- a/src/test/resources/server.js
+++ b/src/test/resources/server.js
@@ -64,6 +64,32 @@ io.of(nsp).on('connection', function(socket) {
   });
 });
 
+
+function before(context, name, fn) {
+  var method = context[name];
+  context[name] = function() {
+    fn.apply(this, arguments);
+    return method.apply(this, arguments);
+  };
+}
+
+before(io.eio, 'handleRequest', function(req, res) {
+  // echo a header value
+  var value = req.headers['x-socketio'];
+  if (!value) return;
+  res.setHeader('X-SocketIO', value);
+});
+
+before(io.eio, 'handleUpgrade', function(req, socket, head) {
+  // echo a header value for websocket handshake
+  var value = req.headers['x-socketio'];
+  if (!value) return;
+  this.ws.once('headers', function(headers) {
+    headers.push('X-SocketIO: ' + value);
+  });
+});
+
+
 server.listen(port, function() {
   console.log('Socket.IO server listening on port', port);
 });