diff --git a/tests/dashboard/test_web_server.py b/tests/dashboard/test_web_server.py
index a61850abf3..74b4c671c9 100644
--- a/tests/dashboard/test_web_server.py
+++ b/tests/dashboard/test_web_server.py
@@ -35,14 +35,14 @@ class DashboardTestHelper:
         return result
 
 
-@pytest_asyncio.fixture()
-async def dashboard() -> DashboardTestHelper:
+@pytest_asyncio.fixture(name="dashboard")
+async def fixture_dashboard() -> DashboardTestHelper:
     sock, port = bind_unused_port()
     args = Mock(
         ha_addon=True,
         configuration=get_fixture_path("conf"),
-        port=port,
     )
+    os.environ["ESPHOME_DASHBOARD_PORT"] = str(port)
     DASHBOARD.settings.parse_args(args)
     app = web_server.make_app()
     http_server = HTTPServer(app)
@@ -52,6 +52,7 @@ async def dashboard() -> DashboardTestHelper:
     assert DASHBOARD.settings.using_password is False
     assert DASHBOARD.settings.on_ha_addon is True
     assert DASHBOARD.settings.using_auth is False
+    assert DASHBOARD.settings.port is port
     task = asyncio.create_task(DASHBOARD.async_run())
     client = AsyncHTTPClient()
     io_loop = IOLoop(make_current=False)