diff --git a/shadowsocks-csharp/Controller/Service/Listener.cs b/shadowsocks-csharp/Controller/Service/Listener.cs
index 9fed2cb7..b2c33262 100644
--- a/shadowsocks-csharp/Controller/Service/Listener.cs
+++ b/shadowsocks-csharp/Controller/Service/Listener.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Net;
 using System.Net.NetworkInformation;
 using System.Net.Sockets;
@@ -10,9 +11,18 @@ namespace Shadowsocks.Controller
 {
     public class Listener
     {
-        public interface Service
+        public interface IService
         {
             bool Handle(byte[] firstPacket, int length, Socket socket, object state);
+
+            void Stop();
+        }
+
+        public abstract class Service : IService
+        {
+            public abstract bool Handle(byte[] firstPacket, int length, Socket socket, object state);
+
+            public virtual void Stop() { }
         }
 
         public class UDPState
@@ -25,9 +35,9 @@ namespace Shadowsocks.Controller
         bool _shareOverLAN;
         Socket _tcpSocket;
         Socket _udpSocket;
-        IList<Service> _services;
+        List<IService> _services;
 
-        public Listener(IList<Service> services)
+        public Listener(List<IService> services)
         {
             this._services = services;
         }
@@ -97,6 +107,8 @@ namespace Shadowsocks.Controller
                 _udpSocket.Close();
                 _udpSocket = null;
             }
+
+            _services.ForEach(s=>s.Stop());
         }
 
         public void RecvFromCallback(IAsyncResult ar)
@@ -105,7 +117,7 @@ namespace Shadowsocks.Controller
             try
             {
                 int bytesRead = _udpSocket.EndReceiveFrom(ar, ref state.remoteEndPoint);
-                foreach (Service service in _services)
+                foreach (IService service in _services)
                 {
                     if (service.Handle(state.buffer, bytesRead, _udpSocket, state))
                     {
@@ -187,7 +199,7 @@ namespace Shadowsocks.Controller
             try
             {
                 int bytesRead = conn.EndReceive(ar);
-                foreach (Service service in _services)
+                foreach (IService service in _services)
                 {
                     if (service.Handle(buf, bytesRead, conn, null))
                     {
diff --git a/shadowsocks-csharp/Controller/Service/PACServer.cs b/shadowsocks-csharp/Controller/Service/PACServer.cs
index c6853331..3fb0461a 100644
--- a/shadowsocks-csharp/Controller/Service/PACServer.cs
+++ b/shadowsocks-csharp/Controller/Service/PACServer.cs
@@ -35,7 +35,7 @@ namespace Shadowsocks.Controller
             this._config = config;
         }
 
-        public bool Handle(byte[] firstPacket, int length, Socket socket, object state)
+        public override bool Handle(byte[] firstPacket, int length, Socket socket, object state)
         {
             if (socket.ProtocolType != ProtocolType.Tcp)
             {
diff --git a/shadowsocks-csharp/Controller/Service/PortForwarder.cs b/shadowsocks-csharp/Controller/Service/PortForwarder.cs
index dcac75bf..6be4dbef 100644
--- a/shadowsocks-csharp/Controller/Service/PortForwarder.cs
+++ b/shadowsocks-csharp/Controller/Service/PortForwarder.cs
@@ -14,7 +14,7 @@ namespace Shadowsocks.Controller
             this._targetPort = targetPort;
         }
 
-        public bool Handle(byte[] firstPacket, int length, Socket socket, object state)
+        public override bool Handle(byte[] firstPacket, int length, Socket socket, object state)
         {
             if (socket.ProtocolType != ProtocolType.Tcp)
             {
diff --git a/shadowsocks-csharp/Controller/Service/TCPRelay.cs b/shadowsocks-csharp/Controller/Service/TCPRelay.cs
index 2d86de25..7a80fefb 100644
--- a/shadowsocks-csharp/Controller/Service/TCPRelay.cs
+++ b/shadowsocks-csharp/Controller/Service/TCPRelay.cs
@@ -29,7 +29,7 @@ namespace Shadowsocks.Controller
             _lastSweepTime = DateTime.Now;
         }
 
-        public bool Handle(byte[] firstPacket, int length, Socket socket, object state)
+        public override bool Handle(byte[] firstPacket, int length, Socket socket, object state)
         {
             if (socket.ProtocolType != ProtocolType.Tcp
                 || (length < 2 || firstPacket[0] != 5))
@@ -62,6 +62,16 @@ namespace Shadowsocks.Controller
             return true;
         }
 
+        public override void Stop()
+        {
+            List<TCPHandler> handlersToClose = new List<TCPHandler>();
+            lock (Handlers)
+            {
+                handlersToClose.AddRange(Handlers);
+            }
+            handlersToClose.ForEach(h=>h.Close());
+        }
+
         public void UpdateInboundCounter(Server server, long n)
         {
             _controller.UpdateInboundCounter(server, n);
diff --git a/shadowsocks-csharp/Controller/Service/UDPRelay.cs b/shadowsocks-csharp/Controller/Service/UDPRelay.cs
index 5f0d2363..e7beb46c 100644
--- a/shadowsocks-csharp/Controller/Service/UDPRelay.cs
+++ b/shadowsocks-csharp/Controller/Service/UDPRelay.cs
@@ -24,7 +24,7 @@ namespace Shadowsocks.Controller
             this._cache = new LRUCache<IPEndPoint, UDPHandler>(512);  // todo: choose a smart number
         }
 
-        public bool Handle(byte[] firstPacket, int length, Socket socket, object state)
+        public override bool Handle(byte[] firstPacket, int length, Socket socket, object state)
         {
             if (socket.ProtocolType != ProtocolType.Udp)
             {
diff --git a/shadowsocks-csharp/Controller/ShadowsocksController.cs b/shadowsocks-csharp/Controller/ShadowsocksController.cs
index a2a34eee..089fbaee 100644
--- a/shadowsocks-csharp/Controller/ShadowsocksController.cs
+++ b/shadowsocks-csharp/Controller/ShadowsocksController.cs
@@ -429,7 +429,7 @@ namespace Shadowsocks.Controller
 
                 TCPRelay tcpRelay = new TCPRelay(this, _config);
                 UDPRelay udpRelay = new UDPRelay(this);
-                List<Listener.Service> services = new List<Listener.Service>();
+                List<Listener.IService> services = new List<Listener.IService>();
                 services.Add(tcpRelay);
                 services.Add(udpRelay);
                 services.Add(_pacServer);