diff --git a/aioworkers_aiohttp/__init__.py b/aioworkers_aiohttp/__init__.py
index 846f823..295bba8 100644
--- a/aioworkers_aiohttp/__init__.py
+++ b/aioworkers_aiohttp/__init__.py
@@ -4,6 +4,8 @@
 
 from aioworkers.core.plugin import Plugin
 
+from .server import WebServer
+
 
 try:
     from .version import __version__
@@ -36,5 +38,5 @@ def parse_known_args(
         namespace: argparse.Namespace,
     ) -> Tuple[argparse.Namespace, Iterable[str]]:
         if namespace.port:
-            self._config['http.port'] = namespace.port
+            WebServer.set_port(namespace.port)
         return namespace, args
diff --git a/aioworkers_aiohttp/server.py b/aioworkers_aiohttp/server.py
index bba6cba..e782c11 100644
--- a/aioworkers_aiohttp/server.py
+++ b/aioworkers_aiohttp/server.py
@@ -4,12 +4,20 @@
 
 
 class WebServer(SocketServer):
+    port = None
+
+    @classmethod
+    def set_port(cls, port: int) -> None:
+        cls.port = port
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self._runner = None
         self._kwargs = {}
 
     def set_config(self, config):
+        if self.port:
+            config = config.new_child(port=self.port)
         super().set_config(config)
         access_log_cls = self.config.get('access_log.cls')
         if access_log_cls: