diff --git a/a8/udplistener.cc b/a8/udplistener.cc
index 0085593..9018886 100644
--- a/a8/udplistener.cc
+++ b/a8/udplistener.cc
@@ -58,7 +58,7 @@ namespace a8
             listen_socket = ::socket(AF_INET, SOCK_DGRAM, 0);
             if (listen_socket == -1){
                 if (master->on_error) {
-                    master->on_error(master, errno);
+                    master->on_error(errno);
                 }
                 return false;
             }
@@ -74,7 +74,7 @@ namespace a8
             sa.sin_port = htons(master->bind_port);
             if (::bind(listen_socket, (sockaddr*)&sa, sizeof(sa)) < 0) {
                 if (master->on_error) {
-                    master->on_error(master, errno);
+                    master->on_error(errno);
                 }
                 ::close(listen_socket);
                 listen_socket = -1;
@@ -113,9 +113,7 @@ namespace a8
                                      (struct sockaddr*)&destAddr,
                                      (socklen_t*)&addrLen);
                 if(ret > 0) {
-                    #if 0
-                    master->OnSocketRead(recv_buf, ret);
-                    #endif
+                    master->on_recv_packet(nullptr);
                 }
             }
         }
diff --git a/a8/udplistener.h b/a8/udplistener.h
index 9330d24..c257ec7 100644
--- a/a8/udplistener.h
+++ b/a8/udplistener.h
@@ -20,8 +20,8 @@ namespace a8
     class UdpListener
     {
     public:
-        std::function<void (a8::UdpListener*, int error_id)> on_error;
-        std::function<void (a8::UdpListener*, UdpPacket*)> on_recv_packet;
+        std::function<void (int error_id)> on_error;
+        std::function<void (UdpPacket*)> on_recv_packet;
         std::string bind_address;
         unsigned short bind_port = 0;