diff --git a/homeassistant/components/brother/__init__.py b/homeassistant/components/brother/__init__.py
index 7c3d3003ea6..c1dbfd5bf0a 100644
--- a/homeassistant/components/brother/__init__.py
+++ b/homeassistant/components/brother/__init__.py
@@ -5,12 +5,12 @@ from datetime import timedelta
 import logging
 
 import async_timeout
-from brother import Brother, DictToObj, SnmpError, UnsupportedModel
-import pysnmp.hlapi.asyncio as SnmpEngine
+from brother import Brother, BrotherSensors, SnmpError, UnsupportedModel
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_HOST, CONF_TYPE, Platform
 from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import ConfigEntryNotReady
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
 
 from .const import DATA_CONFIG_ENTRY, DOMAIN, SNMP
@@ -26,13 +26,17 @@ _LOGGER = logging.getLogger(__name__)
 async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Set up Brother from a config entry."""
     host = entry.data[CONF_HOST]
-    kind = entry.data[CONF_TYPE]
+    printer_type = entry.data[CONF_TYPE]
 
     snmp_engine = get_snmp_engine(hass)
+    try:
+        brother = await Brother.create(
+            host, printer_type=printer_type, snmp_engine=snmp_engine
+        )
+    except (ConnectionError, SnmpError) as error:
+        raise ConfigEntryNotReady from error
 
-    coordinator = BrotherDataUpdateCoordinator(
-        hass, host=host, kind=kind, snmp_engine=snmp_engine
-    )
+    coordinator = BrotherDataUpdateCoordinator(hass, brother)
     await coordinator.async_config_entry_first_refresh()
 
     hass.data.setdefault(DOMAIN, {})
@@ -61,11 +65,9 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
 class BrotherDataUpdateCoordinator(DataUpdateCoordinator):
     """Class to manage fetching Brother data from the printer."""
 
-    def __init__(
-        self, hass: HomeAssistant, host: str, kind: str, snmp_engine: SnmpEngine
-    ) -> None:
+    def __init__(self, hass: HomeAssistant, brother: Brother) -> None:
         """Initialize."""
-        self.brother = Brother(host, kind=kind, snmp_engine=snmp_engine)
+        self.brother = brother
 
         super().__init__(
             hass,
@@ -74,7 +76,7 @@ class BrotherDataUpdateCoordinator(DataUpdateCoordinator):
             update_interval=SCAN_INTERVAL,
         )
 
-    async def _async_update_data(self) -> DictToObj:
+    async def _async_update_data(self) -> BrotherSensors:
         """Update data via library."""
         try:
             async with async_timeout.timeout(20):
diff --git a/homeassistant/components/brother/config_flow.py b/homeassistant/components/brother/config_flow.py
index 27f3c73cd63..48c73d0c4d1 100644
--- a/homeassistant/components/brother/config_flow.py
+++ b/homeassistant/components/brother/config_flow.py
@@ -46,7 +46,9 @@ class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
 
                 snmp_engine = get_snmp_engine(self.hass)
 
-                brother = Brother(user_input[CONF_HOST], snmp_engine=snmp_engine)
+                brother = await Brother.create(
+                    user_input[CONF_HOST], snmp_engine=snmp_engine
+                )
                 await brother.async_update()
 
                 await self.async_set_unique_id(brother.serial.lower())
@@ -80,7 +82,9 @@ class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         model = discovery_info.properties.get("product")
 
         try:
-            self.brother = Brother(self.host, snmp_engine=snmp_engine, model=model)
+            self.brother = await Brother.create(
+                self.host, snmp_engine=snmp_engine, model=model
+            )
             await self.brother.async_update()
         except UnsupportedModel:
             return self.async_abort(reason="unsupported_model")
diff --git a/homeassistant/components/brother/diagnostics.py b/homeassistant/components/brother/diagnostics.py
index 9ff515004cb..239d4916d6b 100644
--- a/homeassistant/components/brother/diagnostics.py
+++ b/homeassistant/components/brother/diagnostics.py
@@ -1,6 +1,8 @@
 """Diagnostics support for Brother."""
 from __future__ import annotations
 
+from dataclasses import asdict
+
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import HomeAssistant
 
@@ -18,7 +20,7 @@ async def async_get_config_entry_diagnostics(
 
     diagnostics_data = {
         "info": dict(config_entry.data),
-        "data": coordinator.data,
+        "data": asdict(coordinator.data),
     }
 
     return diagnostics_data
diff --git a/homeassistant/components/brother/manifest.json b/homeassistant/components/brother/manifest.json
index e14079f6dd9..61b1d8bcdc9 100644
--- a/homeassistant/components/brother/manifest.json
+++ b/homeassistant/components/brother/manifest.json
@@ -3,7 +3,7 @@
   "name": "Brother Printer",
   "documentation": "https://www.home-assistant.io/integrations/brother",
   "codeowners": ["@bieniu"],
-  "requirements": ["brother==1.2.3"],
+  "requirements": ["brother==2.0.0"],
   "zeroconf": [
     {
       "type": "_printer._tcp.local.",
diff --git a/homeassistant/components/brother/sensor.py b/homeassistant/components/brother/sensor.py
index b6af96087af..86f1d2d40ec 100644
--- a/homeassistant/components/brother/sensor.py
+++ b/homeassistant/components/brother/sensor.py
@@ -3,9 +3,11 @@ from __future__ import annotations
 
 from dataclasses import dataclass
 from datetime import datetime
+import logging
 from typing import Any, cast
 
 from homeassistant.components.sensor import (
+    DOMAIN as PLATFORM,
     SensorDeviceClass,
     SensorEntity,
     SensorEntityDescription,
@@ -14,6 +16,7 @@ from homeassistant.components.sensor import (
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_HOST, PERCENTAGE
 from homeassistant.core import HomeAssistant
+from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.entity import DeviceInfo, EntityCategory
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 from homeassistant.helpers.typing import StateType
@@ -28,7 +31,7 @@ ATTR_BLACK_DRUM_REMAINING_LIFE = "black_drum_remaining_life"
 ATTR_BLACK_DRUM_REMAINING_PAGES = "black_drum_remaining_pages"
 ATTR_BLACK_INK_REMAINING = "black_ink_remaining"
 ATTR_BLACK_TONER_REMAINING = "black_toner_remaining"
-ATTR_BW_COUNTER = "b/w_counter"
+ATTR_BW_COUNTER = "bw_counter"
 ATTR_COLOR_COUNTER = "color_counter"
 ATTR_COUNTER = "counter"
 ATTR_CYAN_DRUM_COUNTER = "cyan_drum_counter"
@@ -82,6 +85,8 @@ ATTRS_MAP: dict[str, tuple[str, str]] = {
     ),
 }
 
+_LOGGER = logging.getLogger(__name__)
+
 
 async def async_setup_entry(
     hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
@@ -89,6 +94,22 @@ async def async_setup_entry(
     """Add Brother entities from a config_entry."""
     coordinator = hass.data[DOMAIN][DATA_CONFIG_ENTRY][entry.entry_id]
 
+    # Due to the change of the attribute name of one sensor, it is necessary to migrate
+    # the unique_id to the new one.
+    entity_registry = er.async_get(hass)
+    old_unique_id = f"{coordinator.data.serial.lower()}_b/w_counter"
+    if entity_id := entity_registry.async_get_entity_id(
+        PLATFORM, DOMAIN, old_unique_id
+    ):
+        new_unique_id = f"{coordinator.data.serial.lower()}_bw_counter"
+        _LOGGER.debug(
+            "Migrating entity %s from old unique ID '%s' to new unique ID '%s'",
+            entity_id,
+            old_unique_id,
+            new_unique_id,
+        )
+        entity_registry.async_update_entity(entity_id, new_unique_id=new_unique_id)
+
     sensors = []
 
     device_info = DeviceInfo(
@@ -97,11 +118,11 @@ async def async_setup_entry(
         manufacturer=ATTR_MANUFACTURER,
         model=coordinator.data.model,
         name=coordinator.data.model,
-        sw_version=getattr(coordinator.data, "firmware", None),
+        sw_version=coordinator.data.firmware,
     )
 
     for description in SENSOR_TYPES:
-        if description.key in coordinator.data:
+        if getattr(coordinator.data, description.key) is not None:
             sensors.append(
                 description.entity_class(coordinator, description, device_info)
             )
diff --git a/requirements_all.txt b/requirements_all.txt
index 8d0bd4ff995..32ac27e2fbb 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -449,7 +449,7 @@ boto3==1.20.24
 broadlink==0.18.2
 
 # homeassistant.components.brother
-brother==1.2.3
+brother==2.0.0
 
 # homeassistant.components.brottsplatskartan
 brottsplatskartan==0.0.1
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index bdba84bb811..8ad195aafc6 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -356,7 +356,7 @@ boschshcpy==0.2.30
 broadlink==0.18.2
 
 # homeassistant.components.brother
-brother==1.2.3
+brother==2.0.0
 
 # homeassistant.components.brunt
 brunt==1.2.0
diff --git a/tests/components/brother/__init__.py b/tests/components/brother/__init__.py
index 57cbe8b71de..8e24c2d8058 100644
--- a/tests/components/brother/__init__.py
+++ b/tests/components/brother/__init__.py
@@ -4,11 +4,14 @@ from unittest.mock import patch
 
 from homeassistant.components.brother.const import DOMAIN
 from homeassistant.const import CONF_HOST, CONF_TYPE
+from homeassistant.core import HomeAssistant
 
 from tests.common import MockConfigEntry, load_fixture
 
 
-async def init_integration(hass, skip_setup=False) -> MockConfigEntry:
+async def init_integration(
+    hass: HomeAssistant, skip_setup: bool = False
+) -> MockConfigEntry:
     """Set up the Brother integration in Home Assistant."""
     entry = MockConfigEntry(
         domain=DOMAIN,
@@ -20,7 +23,7 @@ async def init_integration(hass, skip_setup=False) -> MockConfigEntry:
     entry.add_to_hass(hass)
 
     if not skip_setup:
-        with patch(
+        with patch("brother.Brother.initialize"), patch(
             "brother.Brother._get_data",
             return_value=json.loads(load_fixture("printer_data.json", "brother")),
         ):
diff --git a/tests/components/brother/fixtures/diagnostics_data.json b/tests/components/brother/fixtures/diagnostics_data.json
index 0199acdd722..fd22f861e8d 100644
--- a/tests/components/brother/fixtures/diagnostics_data.json
+++ b/tests/components/brother/fixtures/diagnostics_data.json
@@ -1,5 +1,10 @@
 {
-  "b/w_counter": 709,
+  "black_counter": null,
+  "black_ink": null,
+  "black_ink_remaining": null,
+  "black_ink_status": null,
+  "cyan_counter": null,
+  "bw_counter": 709,
   "belt_unit_remaining_life": 97,
   "belt_unit_remaining_pages": 48436,
   "black_drum_counter": 1611,
@@ -12,6 +17,9 @@
   "cyan_drum_counter": 1611,
   "cyan_drum_remaining_life": 92,
   "cyan_drum_remaining_pages": 16389,
+  "cyan_ink": null,
+  "cyan_ink_remaining": null,
+  "cyan_ink_status": null,
   "cyan_toner": 10,
   "cyan_toner_remaining": 10,
   "cyan_toner_status": 1,
@@ -22,10 +30,17 @@
   "duplex_unit_pages_counter": 538,
   "firmware": "1.17",
   "fuser_remaining_life": 97,
+  "fuser_unit_remaining_pages": null,
+  "image_counter": null,
+  "laser_remaining_life": null,
   "laser_unit_remaining_pages": 48389,
+  "magenta_counter": null,
   "magenta_drum_counter": 1611,
   "magenta_drum_remaining_life": 92,
   "magenta_drum_remaining_pages": 16389,
+  "magenta_ink": null,
+  "magenta_ink_remaining": null,
+  "magenta_ink_status": null,
   "magenta_toner": 10,
   "magenta_toner_remaining": 8,
   "magenta_toner_status": 2,
@@ -33,12 +48,18 @@
   "page_counter": 986,
   "pf_kit_1_remaining_life": 98,
   "pf_kit_1_remaining_pages": 48741,
+  "pf_kit_mp_remaining_life": null,
+  "pf_kit_mp_remaining_pages": null,
   "serial": "0123456789",
   "status": "waiting",
   "uptime": "2019-09-24T12:14:56+00:00",
+  "yellow_counter": null,
   "yellow_drum_counter": 1611,
   "yellow_drum_remaining_life": 92,
   "yellow_drum_remaining_pages": 16389,
+  "yellow_ink": null,
+  "yellow_ink_remaining": null,
+  "yellow_ink_status": null,
   "yellow_toner": 10,
   "yellow_toner_remaining": 2,
   "yellow_toner_status": 2
diff --git a/tests/components/brother/test_config_flow.py b/tests/components/brother/test_config_flow.py
index 60f29dbd901..5a145edf030 100644
--- a/tests/components/brother/test_config_flow.py
+++ b/tests/components/brother/test_config_flow.py
@@ -9,13 +9,14 @@ from homeassistant.components import zeroconf
 from homeassistant.components.brother.const import DOMAIN
 from homeassistant.config_entries import SOURCE_USER, SOURCE_ZEROCONF
 from homeassistant.const import CONF_HOST, CONF_TYPE
+from homeassistant.core import HomeAssistant
 
 from tests.common import MockConfigEntry, load_fixture
 
 CONFIG = {CONF_HOST: "127.0.0.1", CONF_TYPE: "laser"}
 
 
-async def test_show_form(hass):
+async def test_show_form(hass: HomeAssistant) -> None:
     """Test that the form is served with no input."""
     result = await hass.config_entries.flow.async_init(
         DOMAIN, context={"source": SOURCE_USER}
@@ -25,9 +26,9 @@ async def test_show_form(hass):
     assert result["step_id"] == SOURCE_USER
 
 
-async def test_create_entry_with_hostname(hass):
+async def test_create_entry_with_hostname(hass: HomeAssistant) -> None:
     """Test that the user step works with printer hostname."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -43,9 +44,9 @@ async def test_create_entry_with_hostname(hass):
         assert result["data"][CONF_TYPE] == "laser"
 
 
-async def test_create_entry_with_ipv4_address(hass):
+async def test_create_entry_with_ipv4_address(hass: HomeAssistant) -> None:
     """Test that the user step works with printer IPv4 address."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -59,9 +60,9 @@ async def test_create_entry_with_ipv4_address(hass):
         assert result["data"][CONF_TYPE] == "laser"
 
 
-async def test_create_entry_with_ipv6_address(hass):
+async def test_create_entry_with_ipv6_address(hass: HomeAssistant) -> None:
     """Test that the user step works with printer IPv6 address."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -77,7 +78,7 @@ async def test_create_entry_with_ipv6_address(hass):
         assert result["data"][CONF_TYPE] == "laser"
 
 
-async def test_invalid_hostname(hass):
+async def test_invalid_hostname(hass: HomeAssistant) -> None:
     """Test invalid hostname in user_input."""
     result = await hass.config_entries.flow.async_init(
         DOMAIN,
@@ -88,9 +89,11 @@ async def test_invalid_hostname(hass):
     assert result["errors"] == {CONF_HOST: "wrong_host"}
 
 
-async def test_connection_error(hass):
+async def test_connection_error(hass: HomeAssistant) -> None:
     """Test connection to host error."""
-    with patch("brother.Brother._get_data", side_effect=ConnectionError()):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=ConnectionError()
+    ):
         result = await hass.config_entries.flow.async_init(
             DOMAIN, context={"source": SOURCE_USER}, data=CONFIG
         )
@@ -98,9 +101,11 @@ async def test_connection_error(hass):
         assert result["errors"] == {"base": "cannot_connect"}
 
 
-async def test_snmp_error(hass):
+async def test_snmp_error(hass: HomeAssistant) -> None:
     """Test SNMP error."""
-    with patch("brother.Brother._get_data", side_effect=SnmpError("error")):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=SnmpError("error")
+    ):
         result = await hass.config_entries.flow.async_init(
             DOMAIN, context={"source": SOURCE_USER}, data=CONFIG
         )
@@ -108,9 +113,11 @@ async def test_snmp_error(hass):
         assert result["errors"] == {"base": "snmp_error"}
 
 
-async def test_unsupported_model_error(hass):
+async def test_unsupported_model_error(hass: HomeAssistant) -> None:
     """Test unsupported printer model error."""
-    with patch("brother.Brother._get_data", side_effect=UnsupportedModel("error")):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=UnsupportedModel("error")
+    ):
 
         result = await hass.config_entries.flow.async_init(
             DOMAIN, context={"source": SOURCE_USER}, data=CONFIG
@@ -120,9 +127,9 @@ async def test_unsupported_model_error(hass):
         assert result["reason"] == "unsupported_model"
 
 
-async def test_device_exists_abort(hass):
+async def test_device_exists_abort(hass: HomeAssistant) -> None:
     """Test we abort config flow if Brother printer already configured."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -137,9 +144,11 @@ async def test_device_exists_abort(hass):
         assert result["reason"] == "already_configured"
 
 
-async def test_zeroconf_snmp_error(hass):
+async def test_zeroconf_snmp_error(hass: HomeAssistant) -> None:
     """Test we abort zeroconf flow on SNMP error."""
-    with patch("brother.Brother._get_data", side_effect=SnmpError("error")):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=SnmpError("error")
+    ):
 
         result = await hass.config_entries.flow.async_init(
             DOMAIN,
@@ -159,9 +168,11 @@ async def test_zeroconf_snmp_error(hass):
         assert result["reason"] == "cannot_connect"
 
 
-async def test_zeroconf_unsupported_model(hass):
+async def test_zeroconf_unsupported_model(hass: HomeAssistant) -> None:
     """Test unsupported printer model error."""
-    with patch("brother.Brother._get_data") as mock_get_data:
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data"
+    ) as mock_get_data:
         result = await hass.config_entries.flow.async_init(
             DOMAIN,
             context={"source": SOURCE_ZEROCONF},
@@ -181,9 +192,9 @@ async def test_zeroconf_unsupported_model(hass):
         assert len(mock_get_data.mock_calls) == 0
 
 
-async def test_zeroconf_device_exists_abort(hass):
+async def test_zeroconf_device_exists_abort(hass: HomeAssistant) -> None:
     """Test we abort zeroconf flow if Brother printer already configured."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -215,11 +226,13 @@ async def test_zeroconf_device_exists_abort(hass):
     assert entry.data["host"] == "127.0.0.1"
 
 
-async def test_zeroconf_no_probe_existing_device(hass):
+async def test_zeroconf_no_probe_existing_device(hass: HomeAssistant) -> None:
     """Test we do not probe the device is the host is already configured."""
     entry = MockConfigEntry(domain=DOMAIN, unique_id="0123456789", data=CONFIG)
     entry.add_to_hass(hass)
-    with patch("brother.Brother._get_data") as mock_get_data:
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data"
+    ) as mock_get_data:
         result = await hass.config_entries.flow.async_init(
             DOMAIN,
             context={"source": SOURCE_ZEROCONF},
@@ -240,9 +253,9 @@ async def test_zeroconf_no_probe_existing_device(hass):
     assert len(mock_get_data.mock_calls) == 0
 
 
-async def test_zeroconf_confirm_create_entry(hass):
+async def test_zeroconf_confirm_create_entry(hass: HomeAssistant) -> None:
     """Test zeroconf confirmation and create config entry."""
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
diff --git a/tests/components/brother/test_diagnostics.py b/tests/components/brother/test_diagnostics.py
index 7e25ffaa4f0..73b3b6dda7a 100644
--- a/tests/components/brother/test_diagnostics.py
+++ b/tests/components/brother/test_diagnostics.py
@@ -1,8 +1,12 @@
 """Test Brother diagnostics."""
+from collections.abc import Awaitable, Callable
 from datetime import datetime
 import json
 from unittest.mock import Mock, patch
 
+from aiohttp import ClientSession
+
+from homeassistant.core import HomeAssistant
 from homeassistant.util.dt import UTC
 
 from tests.common import load_fixture
@@ -10,13 +14,17 @@ from tests.components.brother import init_integration
 from tests.components.diagnostics import get_diagnostics_for_config_entry
 
 
-async def test_entry_diagnostics(hass, hass_client):
+async def test_entry_diagnostics(
+    hass: HomeAssistant, hass_client: Callable[..., Awaitable[ClientSession]]
+) -> None:
     """Test config entry diagnostics."""
     entry = await init_integration(hass, skip_setup=True)
 
     diagnostics_data = json.loads(load_fixture("diagnostics_data.json", "brother"))
     test_time = datetime(2019, 11, 11, 9, 10, 32, tzinfo=UTC)
-    with patch("brother.datetime", utcnow=Mock(return_value=test_time)), patch(
+    with patch("brother.Brother.initialize"), patch(
+        "brother.datetime", utcnow=Mock(return_value=test_time)
+    ), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
diff --git a/tests/components/brother/test_init.py b/tests/components/brother/test_init.py
index 76b999c3e54..b034259974a 100644
--- a/tests/components/brother/test_init.py
+++ b/tests/components/brother/test_init.py
@@ -1,15 +1,19 @@
 """Test init of Brother integration."""
 from unittest.mock import patch
 
+from brother import SnmpError
+import pytest
+
 from homeassistant.components.brother.const import DOMAIN
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.const import CONF_HOST, CONF_TYPE, STATE_UNAVAILABLE
+from homeassistant.core import HomeAssistant
 
 from tests.common import MockConfigEntry
 from tests.components.brother import init_integration
 
 
-async def test_async_setup_entry(hass):
+async def test_async_setup_entry(hass: HomeAssistant) -> None:
     """Test a successful setup entry."""
     await init_integration(hass)
 
@@ -19,7 +23,7 @@ async def test_async_setup_entry(hass):
     assert state.state == "waiting"
 
 
-async def test_config_not_ready(hass):
+async def test_config_not_ready(hass: HomeAssistant) -> None:
     """Test for setup failure if connection to broker is missing."""
     entry = MockConfigEntry(
         domain=DOMAIN,
@@ -28,13 +32,31 @@ async def test_config_not_ready(hass):
         data={CONF_HOST: "localhost", CONF_TYPE: "laser"},
     )
 
-    with patch("brother.Brother._get_data", side_effect=ConnectionError()):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=ConnectionError()
+    ):
         entry.add_to_hass(hass)
         await hass.config_entries.async_setup(entry.entry_id)
         assert entry.state is ConfigEntryState.SETUP_RETRY
 
 
-async def test_unload_entry(hass):
+@pytest.mark.parametrize("exc", [(SnmpError("SNMP Error")), (ConnectionError)])
+async def test_error_on_init(hass: HomeAssistant, exc: Exception) -> None:
+    """Test for error on init."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        title="HL-L2340DW 0123456789",
+        unique_id="0123456789",
+        data={CONF_HOST: "localhost", CONF_TYPE: "laser"},
+    )
+
+    with patch("brother.Brother.initialize", side_effect=exc):
+        entry.add_to_hass(hass)
+        await hass.config_entries.async_setup(entry.entry_id)
+        assert entry.state is ConfigEntryState.SETUP_RETRY
+
+
+async def test_unload_entry(hass: HomeAssistant) -> None:
     """Test successful unload of entry."""
     entry = await init_integration(hass)
 
diff --git a/tests/components/brother/test_sensor.py b/tests/components/brother/test_sensor.py
index 7ef87a2e396..f50104c0b3a 100644
--- a/tests/components/brother/test_sensor.py
+++ b/tests/components/brother/test_sensor.py
@@ -19,6 +19,7 @@ from homeassistant.const import (
     PERCENTAGE,
     STATE_UNAVAILABLE,
 )
+from homeassistant.core import HomeAssistant
 from homeassistant.helpers import entity_registry as er
 from homeassistant.setup import async_setup_component
 from homeassistant.util.dt import UTC, utcnow
@@ -30,7 +31,7 @@ ATTR_REMAINING_PAGES = "remaining_pages"
 ATTR_COUNTER = "counter"
 
 
-async def test_sensors(hass):
+async def test_sensors(hass: HomeAssistant) -> None:
     """Test states of the sensors."""
     entry = await init_integration(hass, skip_setup=True)
 
@@ -45,7 +46,9 @@ async def test_sensors(hass):
         disabled_by=None,
     )
     test_time = datetime(2019, 11, 11, 9, 10, 32, tzinfo=UTC)
-    with patch("brother.datetime", utcnow=Mock(return_value=test_time)), patch(
+    with patch("brother.Brother.initialize"), patch(
+        "brother.datetime", utcnow=Mock(return_value=test_time)
+    ), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -235,7 +238,7 @@ async def test_sensors(hass):
 
     entry = registry.async_get("sensor.hl_l2340dw_b_w_counter")
     assert entry
-    assert entry.unique_id == "0123456789_b/w_counter"
+    assert entry.unique_id == "0123456789_bw_counter"
 
     state = hass.states.get("sensor.hl_l2340dw_color_counter")
     assert state
@@ -276,7 +279,7 @@ async def test_disabled_by_default_sensors(hass):
     assert entry.disabled_by is er.RegistryEntryDisabler.INTEGRATION
 
 
-async def test_availability(hass):
+async def test_availability(hass: HomeAssistant) -> None:
     """Ensure that we mark the entities unavailable correctly when device is offline."""
     await init_integration(hass)
 
@@ -286,7 +289,9 @@ async def test_availability(hass):
     assert state.state == "waiting"
 
     future = utcnow() + timedelta(minutes=5)
-    with patch("brother.Brother._get_data", side_effect=ConnectionError()):
+    with patch("brother.Brother.initialize"), patch(
+        "brother.Brother._get_data", side_effect=ConnectionError()
+    ):
         async_fire_time_changed(hass, future)
         await hass.async_block_till_done()
 
@@ -295,7 +300,7 @@ async def test_availability(hass):
         assert state.state == STATE_UNAVAILABLE
 
     future = utcnow() + timedelta(minutes=10)
-    with patch(
+    with patch("brother.Brother.initialize"), patch(
         "brother.Brother._get_data",
         return_value=json.loads(load_fixture("printer_data.json", "brother")),
     ):
@@ -308,7 +313,7 @@ async def test_availability(hass):
         assert state.state == "waiting"
 
 
-async def test_manual_update_entity(hass):
+async def test_manual_update_entity(hass: HomeAssistant) -> None:
     """Test manual update entity via service homeassistant/update_entity."""
     await init_integration(hass)
 
@@ -326,3 +331,22 @@ async def test_manual_update_entity(hass):
         )
 
         assert len(mock_update.mock_calls) == 1
+
+
+async def test_unique_id_migration(hass: HomeAssistant) -> None:
+    """Test states of the unique_id migration."""
+    registry = er.async_get(hass)
+
+    registry.async_get_or_create(
+        SENSOR_DOMAIN,
+        DOMAIN,
+        "0123456789_b/w_counter",
+        suggested_object_id="hl_l2340dw_b_w_counter",
+        disabled_by=None,
+    )
+
+    await init_integration(hass)
+
+    entry = registry.async_get("sensor.hl_l2340dw_b_w_counter")
+    assert entry
+    assert entry.unique_id == "0123456789_bw_counter"