diff --git a/homeassistant/components/brunt/__init__.py b/homeassistant/components/brunt/__init__.py
index f189be63920..979b3f5b005 100644
--- a/homeassistant/components/brunt/__init__.py
+++ b/homeassistant/components/brunt/__init__.py
@@ -5,7 +5,7 @@ import logging
 
 from aiohttp.client_exceptions import ClientResponseError, ServerDisconnectedError
 import async_timeout
-from brunt import BruntClientAsync
+from brunt import BruntClientAsync, Thing
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_PASSWORD, CONF_USERNAME
@@ -36,7 +36,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             f"Brunt could not connect with username: {entry.data[CONF_USERNAME]}."
         ) from exc
 
-    async def async_update_data():
+    async def async_update_data() -> dict[str | None, Thing]:
         """Fetch data from the Brunt endpoint for all Things.
 
         Error 403 is the API response for any kind of authentication error (failed password or email)
@@ -54,6 +54,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             if err.status == 401:
                 _LOGGER.warning("Device not found, will reload Brunt integration")
                 await hass.config_entries.async_reload(entry.entry_id)
+            raise UpdateFailed from err
 
     coordinator = DataUpdateCoordinator(
         hass,
diff --git a/homeassistant/components/brunt/cover.py b/homeassistant/components/brunt/cover.py
index 489229622b2..599008adc60 100644
--- a/homeassistant/components/brunt/cover.py
+++ b/homeassistant/components/brunt/cover.py
@@ -1,7 +1,7 @@
 """Support for Brunt Blind Engine covers."""
 from __future__ import annotations
 
-from typing import Any
+from typing import Any, Optional
 
 from aiohttp.client_exceptions import ClientResponseError
 from brunt import BruntClientAsync, Thing
@@ -42,7 +42,9 @@ async def async_setup_entry(
 ) -> None:
     """Set up the brunt platform."""
     bapi: BruntClientAsync = hass.data[DOMAIN][entry.entry_id][DATA_BAPI]
-    coordinator: DataUpdateCoordinator = hass.data[DOMAIN][entry.entry_id][DATA_COOR]
+    coordinator: DataUpdateCoordinator[dict[str | None, Thing]] = hass.data[DOMAIN][
+        entry.entry_id
+    ][DATA_COOR]
 
     async_add_entities(
         BruntDevice(coordinator, serial, thing, bapi, entry.entry_id)
@@ -50,7 +52,9 @@ async def async_setup_entry(
     )
 
 
-class BruntDevice(CoordinatorEntity, CoverEntity):
+class BruntDevice(
+    CoordinatorEntity[DataUpdateCoordinator[dict[Optional[str], Thing]]], CoverEntity
+):
     """
     Representation of a Brunt cover device.
 
@@ -65,8 +69,8 @@ class BruntDevice(CoordinatorEntity, CoverEntity):
 
     def __init__(
         self,
-        coordinator: DataUpdateCoordinator,
-        serial: str,
+        coordinator: DataUpdateCoordinator[dict[str | None, Thing]],
+        serial: str | None,
         thing: Thing,
         bapi: BruntClientAsync,
         entry_id: str,
@@ -84,7 +88,7 @@ class BruntDevice(CoordinatorEntity, CoverEntity):
         self._attr_device_class = CoverDeviceClass.BLIND
         self._attr_attribution = ATTRIBUTION
         self._attr_device_info = DeviceInfo(
-            identifiers={(DOMAIN, self._attr_unique_id)},
+            identifiers={(DOMAIN, self._attr_unique_id)},  # type: ignore[arg-type]
             name=self._attr_name,
             via_device=(DOMAIN, self._entry_id),
             manufacturer="Brunt",