diff --git a/nanobot/cli/commands.py b/nanobot/cli/commands.py
index 2c8d6d3..37f08b2 100644
--- a/nanobot/cli/commands.py
+++ b/nanobot/cli/commands.py
@@ -290,7 +290,7 @@ def _load_runtime_config(config: str | None = None, workspace: str | None = None
 
 @app.command()
 def gateway(
-    port: int = typer.Option(18790, "--port", "-p", help="Gateway port"),
+    port: int | None = typer.Option(None, "--port", "-p", help="Gateway port"),
     workspace: str | None = typer.Option(None, "--workspace", "-w", help="Workspace directory"),
     verbose: bool = typer.Option(False, "--verbose", "-v", help="Verbose output"),
     config: str | None = typer.Option(None, "--config", "-c", help="Path to config file"),
@@ -310,6 +310,7 @@ def gateway(
         logging.basicConfig(level=logging.DEBUG)
 
     config = _load_runtime_config(config, workspace)
+    port = port if port is not None else config.gateway.port
 
     console.print(f"{__logo__} Starting nanobot gateway on port {port}...")
     sync_workspace_templates(config.workspace_path)
diff --git a/tests/test_commands.py b/tests/test_commands.py
index 19c1998..5d38942 100644
--- a/tests/test_commands.py
+++ b/tests/test_commands.py
@@ -356,3 +356,47 @@ def test_gateway_uses_config_directory_for_cron_store(monkeypatch, tmp_path: Pat
 
     assert isinstance(result.exception, _StopGateway)
     assert seen["cron_store"] == config_file.parent / "cron" / "jobs.json"
+
+
+def test_gateway_uses_configured_port_when_cli_flag_is_missing(monkeypatch, tmp_path: Path) -> None:
+    config_file = tmp_path / "instance" / "config.json"
+    config_file.parent.mkdir(parents=True)
+    config_file.write_text("{}")
+
+    config = Config()
+    config.gateway.port = 18791
+
+    monkeypatch.setattr("nanobot.config.loader.set_config_path", lambda _path: None)
+    monkeypatch.setattr("nanobot.config.loader.load_config", lambda _path=None: config)
+    monkeypatch.setattr("nanobot.cli.commands.sync_workspace_templates", lambda _path: None)
+    monkeypatch.setattr(
+        "nanobot.cli.commands._make_provider",
+        lambda _config: (_ for _ in ()).throw(_StopGateway("stop")),
+    )
+
+    result = runner.invoke(app, ["gateway", "--config", str(config_file)])
+
+    assert isinstance(result.exception, _StopGateway)
+    assert "port 18791" in result.stdout
+
+
+def test_gateway_cli_port_overrides_configured_port(monkeypatch, tmp_path: Path) -> None:
+    config_file = tmp_path / "instance" / "config.json"
+    config_file.parent.mkdir(parents=True)
+    config_file.write_text("{}")
+
+    config = Config()
+    config.gateway.port = 18791
+
+    monkeypatch.setattr("nanobot.config.loader.set_config_path", lambda _path: None)
+    monkeypatch.setattr("nanobot.config.loader.load_config", lambda _path=None: config)
+    monkeypatch.setattr("nanobot.cli.commands.sync_workspace_templates", lambda _path: None)
+    monkeypatch.setattr(
+        "nanobot.cli.commands._make_provider",
+        lambda _config: (_ for _ in ()).throw(_StopGateway("stop")),
+    )
+
+    result = runner.invoke(app, ["gateway", "--config", str(config_file), "--port", "18792"])
+
+    assert isinstance(result.exception, _StopGateway)
+    assert "port 18792" in result.stdout