diff --git a/lib/tfw/networking/server/zmq_websocket_proxy.py b/lib/tfw/networking/server/zmq_websocket_proxy.py
index 3fc5bff..7a38e4a 100644
--- a/lib/tfw/networking/server/zmq_websocket_proxy.py
+++ b/lib/tfw/networking/server/zmq_websocket_proxy.py
@@ -17,13 +17,10 @@ class ZMQWebSocketProxy(WebSocketHandler):
     def initialize(self, **kwargs): # pylint: disable=arguments-differ
         self._event_handler_connector = kwargs['event_handler_connector']
 
-        self.init_callback_lists_from(
-            kwargs,
-            [
-                'message_handlers',
-                'proxy_filters'
-            ]
-        )
+        self._message_handlers = kwargs.get('message_handlers', [])
+        self._frontend_message_handlers = kwargs.get('frontend_message_handlers', [])
+        self._eventhandler_message_handlers = kwargs.get('eventhandler_message_handlers', [])
+        self._proxy_filters = kwargs.get('proxy_filters', [])
 
         self.proxy_eventhandler_to_websocket = TFWProxy(
             self.send_eventhandler_message,
@@ -36,22 +33,16 @@ class ZMQWebSocketProxy(WebSocketHandler):
 
         self.subscribe_proxy_callbacks()
 
-    def init_callback_lists_from(self, init_kwargs, callback_lists):
-        for callback_list in callback_lists:
-            setattr(
-                self,
-                f'_{callback_list}',
-                init_kwargs.get(callback_list, [])
-            )
-
     def subscribe_proxy_callbacks(self):
-        proxies = (
-            self.proxy_eventhandler_to_websocket,
-            self.proxy_websocket_to_eventhandler
+        self.proxy_websocket_to_eventhandler.subscribe_proxy_callbacks_and_filters(
+            self._eventhandler_message_handlers + self._message_handlers,
+            self._proxy_filters
+        )
+
+        self.proxy_eventhandler_to_websocket.subscribe_proxy_callbacks_and_filters(
+            self._frontend_message_handlers + self._message_handlers,
+            self._proxy_filters
         )
-        for proxy in proxies:
-            proxy.proxy_filters.subscribe_callbacks(*self._proxy_filters)
-            proxy.proxy_callbacks.subscribe_callbacks(*self._message_handlers)
 
     def prepare(self):
         ZMQWebSocketProxy.instances.add(self)
@@ -139,3 +130,7 @@ class TFWProxy:
         LOG.debug('Broadcasting message: %s', message)
         self.to_source(message)
         self.to_destination(message)
+
+    def subscribe_proxy_callbacks_and_filters(self, proxy_callbacks, proxy_filters):
+        self.proxy_callbacks.subscribe_callbacks(*proxy_callbacks)
+        self.proxy_filters.subscribe_callbacks(*proxy_filters)