diff --git a/aiosocks/protocols.py b/aiosocks/protocols.py
index bd7cbcf..c5ff3a7 100644
--- a/aiosocks/protocols.py
+++ b/aiosocks/protocols.py
@@ -19,7 +19,7 @@ except ImportError:
 class BaseSocksProtocol(asyncio.StreamReaderProtocol):
     def __init__(self, proxy, proxy_auth, dst, app_protocol_factory, waiter,
                  remote_resolve=True, loop=None, ssl=False,
-                 server_hostname=None):
+                 server_hostname=None, negotiate_done_cb=None):
         if not isinstance(dst, (tuple, list)) or len(dst) != 2:
             raise ValueError(
                 'Invalid dst format, tuple("dst_host", dst_port))'
@@ -29,13 +29,14 @@ class BaseSocksProtocol(asyncio.StreamReaderProtocol):
         self._auth = proxy_auth
         self._dst_host, self._dst_port = dst
         self._remote_resolve = remote_resolve
-
-        self._loop = loop or asyncio.get_event_loop()
-        self._transport = None
         self._waiter = waiter
-        self._negotiate_fut = None
         self._ssl = ssl
         self._server_hostname = server_hostname
+        self._negotiate_done_cb = negotiate_done_cb
+        self._loop = loop or asyncio.get_event_loop()
+
+        self._transport = None
+        self._negotiate_done = False
 
         if app_protocol_factory:
             self._app_protocol = app_protocol_factory()
@@ -44,7 +45,41 @@ class BaseSocksProtocol(asyncio.StreamReaderProtocol):
 
         reader = asyncio.StreamReader(loop=self._loop)
 
-        super().__init__(stream_reader=reader, loop=self._loop)
+        super().__init__(stream_reader=reader,
+                         client_connected_cb=self.negotiate, loop=self._loop)
+
+    @asyncio.coroutine
+    def negotiate(self, reader, writer):
+        try:
+            req = self.socks_request(c.SOCKS_CMD_CONNECT)
+            self._proxy_peername, self._proxy_sockname = yield from req
+        except SocksError as exc:
+            exc = SocksError('Can not connect to %s:%s. %s' %
+                             (self._dst_host, self._dst_port, exc))
+            self._loop.call_soon(self._waiter.set_exception, exc)
+        except Exception as exc:
+            self._loop.call_soon(self._waiter.set_exception, exc)
+        else:
+            self._negotiate_done = True
+
+            if self._ssl:
+                sock = self._transport.get_extra_info('socket')
+
+                self._transport = self._loop._make_ssl_transport(
+                    rawsock=sock, protocol=self._app_protocol,
+                    sslcontext=self._ssl, server_side=False,
+                    server_hostname=self._server_hostname,
+                    waiter=self._waiter)
+            else:
+                self._loop.call_soon(self._app_protocol.connection_made,
+                                     self._transport)
+                self._loop.call_soon(self._waiter.set_result, True)
+
+            if self._negotiate_done_cb is not None:
+                res = self._negotiate_done_cb(reader, writer)
+
+                if asyncio.iscoroutine(res):
+                    asyncio.Task(res, loop=self._loop)
 
     def connection_made(self, transport):
         # connection_made is called
@@ -54,55 +89,31 @@ class BaseSocksProtocol(asyncio.StreamReaderProtocol):
         super().connection_made(transport)
         self._transport = transport
 
-        def init_app_protocol(fut):
-            exc = fut.exception()
-            if exc:
-                if isinstance(exc, SocksError):
-                    exc = SocksError('Can not connect to %s:%s. %s' %
-                                     (self._dst_host, self._dst_port, exc))
-                self._waiter.set_exception(exc)
-            else:
-                if self._ssl:
-                    sock = self._transport.get_extra_info('socket')
-
-                    self._transport = self._loop._make_ssl_transport(
-                        rawsock=sock, protocol=self._app_protocol,
-                        sslcontext=self._ssl, server_side=False,
-                        server_hostname=self._server_hostname,
-                        waiter=self._waiter)
-                else:
-                    self._app_protocol.connection_made(transport)
-                    self._waiter.set_result(True)
-
-        req_coro = self.socks_request(c.SOCKS_CMD_CONNECT)
-        self._negotiate_fut = ensure_future(req_coro, loop=self._loop)
-        self._negotiate_fut.add_done_callback(init_app_protocol)
-
     def connection_lost(self, exc):
-        if self._negotiate_fut.done() and not self._negotiate_fut.exception():
+        if self._negotiate_done and self._app_protocol is not self:
             self._loop.call_soon(self._app_protocol.connection_lost, exc)
         super().connection_lost(exc)
 
     def pause_writing(self):
-        if self._negotiate_fut.done():
+        if self._negotiate_done and self._app_protocol is not self:
             self._app_protocol.pause_writing()
         else:
             super().pause_writing()
 
     def resume_writing(self):
-        if self._negotiate_fut.done():
+        if self._negotiate_done and self._app_protocol is not self:
             self._app_protocol.resume_writing()
         else:
             super().resume_writing()
 
     def data_received(self, data):
-        if self._negotiate_fut.done():
+        if self._negotiate_done and self._app_protocol is not self:
             self._app_protocol.data_received(data)
         else:
             super().data_received(data)
 
     def eof_received(self):
-        if self._negotiate_fut.done() and not self._negotiate_fut.exception():
+        if self._negotiate_done and self._app_protocol is not self:
             self._app_protocol.eof_received()
         super().eof_received()
 
@@ -120,8 +131,7 @@ class BaseSocksProtocol(asyncio.StreamReaderProtocol):
                 bdata += item
             else:
                 raise ValueError('Unsupported item')
-
-        self._transport.write(bdata)
+        self._stream_writer.write(bdata)
 
     @asyncio.coroutine
     def read_response(self, n):