diff --git a/src/node/socket.h b/src/node/socket.h
index 21f060ca0..1c4e650e0 100644
--- a/src/node/socket.h
+++ b/src/node/socket.h
@@ -501,7 +501,7 @@ protected:
   void NotifyDataSent (uint32_t size);
   void NotifySend (uint32_t spaceAvailable);
   void NotifyDataRecv (void);
-
+private:
   Callback<void, Ptr<Socket> >   m_connectionSucceeded;
   Callback<void, Ptr<Socket> >   m_connectionFailed;
   Callback<bool, Ptr<Socket>, const Address &>   m_connectionRequest;