diff --git a/.strict-typing b/.strict-typing
index 19835bfd777..0a226f973f6 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -65,6 +65,7 @@ homeassistant.components.netatmo.*
 homeassistant.components.network.*
 homeassistant.components.no_ip.*
 homeassistant.components.notify.*
+homeassistant.components.notion.*
 homeassistant.components.number.*
 homeassistant.components.onewire.*
 homeassistant.components.persistent_notification.*
diff --git a/homeassistant/components/notion/__init__.py b/homeassistant/components/notion/__init__.py
index 8acf9c24d4a..aab10916514 100644
--- a/homeassistant/components/notion/__init__.py
+++ b/homeassistant/components/notion/__init__.py
@@ -1,6 +1,9 @@
 """Support for Notion."""
+from __future__ import annotations
+
 import asyncio
 from datetime import timedelta
+from typing import Any
 
 from aionotion import async_get_client
 from aionotion.errors import InvalidCredentialsError, NotionError
@@ -55,9 +58,9 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         LOGGER.error("Config entry failed: %s", err)
         raise ConfigEntryNotReady from err
 
-    async def async_update():
+    async def async_update() -> dict[str, dict[str, Any]]:
         """Get the latest data from the Notion API."""
-        data = {"bridges": {}, "sensors": {}, "tasks": {}}
+        data: dict[str, dict[str, Any]] = {"bridges": {}, "sensors": {}, "tasks": {}}
         tasks = {
             "bridges": client.bridge.async_all(),
             "sensors": client.sensor.async_all(),
@@ -111,7 +114,7 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
 
 async def async_register_new_bridge(
     hass: HomeAssistant, bridge: dict, entry: ConfigEntry
-):
+) -> None:
     """Register a new bridge."""
     device_registry = await dr.async_get_registry(hass)
     device_registry.async_get_or_create(
@@ -190,13 +193,16 @@ class NotionEntity(CoordinatorEntity):
         self._bridge_id = sensor["bridge"]["id"]
 
         device_registry = await dr.async_get_registry(self.hass)
+        this_device = device_registry.async_get_device(
+            {(DOMAIN, sensor["hardware_id"])}
+        )
         bridge = self.coordinator.data["bridges"][self._bridge_id]
         bridge_device = device_registry.async_get_device(
             {(DOMAIN, bridge["hardware_id"])}
         )
-        this_device = device_registry.async_get_device(
-            {(DOMAIN, sensor["hardware_id"])}
-        )
+
+        if not bridge_device or not this_device:
+            return
 
         device_registry.async_update_device(
             this_device.id, via_device_id=bridge_device.id
diff --git a/mypy.ini b/mypy.ini
index e0bdc372f50..014272f0022 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -726,6 +726,17 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.notion.*]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+no_implicit_optional = true
+warn_return_any = true
+warn_unreachable = true
+
 [mypy-homeassistant.components.number.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true
@@ -1422,9 +1433,6 @@ ignore_errors = true
 [mypy-homeassistant.components.norway_air.*]
 ignore_errors = true
 
-[mypy-homeassistant.components.notion.*]
-ignore_errors = true
-
 [mypy-homeassistant.components.nsw_fuel_station.*]
 ignore_errors = true
 
diff --git a/script/hassfest/mypy_config.py b/script/hassfest/mypy_config.py
index b1c74fceb45..642dd47b732 100644
--- a/script/hassfest/mypy_config.py
+++ b/script/hassfest/mypy_config.py
@@ -114,7 +114,6 @@ IGNORED_MODULES: Final[list[str]] = [
     "homeassistant.components.nilu.*",
     "homeassistant.components.nmap_tracker.*",
     "homeassistant.components.norway_air.*",
-    "homeassistant.components.notion.*",
     "homeassistant.components.nsw_fuel_station.*",
     "homeassistant.components.nuki.*",
     "homeassistant.components.nws.*",