diff --git a/python/src/wslink/backends/aiohttp/__init__.py b/python/src/wslink/backends/aiohttp/__init__.py
index 473b92d..ecde93d 100644
--- a/python/src/wslink/backends/aiohttp/__init__.py
+++ b/python/src/wslink/backends/aiohttp/__init__.py
@@ -35,10 +35,10 @@ def _fix_path(path):
 # -----------------------------------------------------------------------------
 
 
-class WebAppServer(AbstractWebApp, aiohttp_web.Application):
+class WebAppServer(AbstractWebApp):
     def __init__(self, server_config):
         AbstractWebApp.__init__(self, server_config)
-        aiohttp_web.Application.__init__(self)
+        self.set_app(aiohttp_web.Application())
         self._ws_handlers = []
         self._site = None
         self._runner = None
@@ -52,7 +52,7 @@ def __init__(self, server_config):
                     aiohttp_web.get(_fix_path(route), protocol_handler.handleWsRequest)
                 )
 
-            self.add_routes(routes)
+            self.app.add_routes(routes)
 
         if "static" in server_config:
             static_routes = server_config["static"]
@@ -68,10 +68,10 @@ def __init__(self, server_config):
                 )
 
             # Resolve / => index.html
-            self.router.add_route("GET", "/", _root_handler)
-            self.add_routes(routes)
+            self.app.router.add_route("GET", "/", _root_handler)
+            self.app.add_routes(routes)
 
-        self["state"] = {}
+        self.app["state"] = {}
 
     # -------------------------------------------------------------------------
     # Server status
@@ -94,7 +94,9 @@ def get_port(self):
     # -------------------------------------------------------------------------
 
     async def start(self, port_callback=None):
-        self._runner = aiohttp_web.AppRunner(self, handle_signals=self.handle_signals)
+        self._runner = aiohttp_web.AppRunner(
+            self.app, handle_signals=self.handle_signals
+        )
 
         logging.info("awaiting runner setup")
         await self._runner.setup()
diff --git a/python/src/wslink/protocol.py b/python/src/wslink/protocol.py
index 6c71fca..027a1f3 100644
--- a/python/src/wslink/protocol.py
+++ b/python/src/wslink/protocol.py
@@ -16,6 +16,7 @@ def __init__(self, server_config):
         self._config = server_config
         self._shutdown_task = None
         self._completion = asyncio.get_event_loop().create_future()
+        self._app = None
 
     # -------------------------------------------------------------------------
     # Config helper
@@ -58,11 +59,22 @@ def last_active_client_id(self, value):
         self._last_active_client_id = value
 
     # -------------------------------------------------------------------------
-    # Legacy / deprecated
+    # Implementation server class
     # -------------------------------------------------------------------------
 
-    def set_app(self, *args):
-        print("DEPRECATED: set_app()")
+    def set_app(self, app):
+        self._app = app
+
+    def get_app(self):
+        return self._app
+
+    @property
+    def app(self):
+        return self._app
+
+    # -------------------------------------------------------------------------
+    # Legacy / deprecated
+    # -------------------------------------------------------------------------
 
     def get_config(self):
         print("DEPRECATED: get_config() use property instead")
@@ -71,14 +83,6 @@ def get_config(self):
     def set_config(self, config):
         print("DEPRECATED: set_config() use constructor instead")
 
-    def get_app(self):
-        print("DEPRECATED: get_app()")
-        return self
-
-    @property
-    def app(self):
-        print("DEPRECATED: .app.")
-
     def get_last_active_client_id(self):
         print(
             "DEPRECATED: get_last_active_client_id() should be replaced by last_active_client_id"