diff --git a/homeassistant/components/timer/__init__.py b/homeassistant/components/timer/__init__.py
index 2e92ddf6fd8..31b9b14c9da 100644
--- a/homeassistant/components/timer/__init__.py
+++ b/homeassistant/components/timer/__init__.py
@@ -3,6 +3,7 @@ from __future__ import annotations
 
 from datetime import datetime, timedelta
 import logging
+from typing import Callable
 
 import voluptuous as vol
 
@@ -196,7 +197,7 @@ class Timer(RestoreEntity):
         self._duration = cv.time_period_str(config[CONF_DURATION])
         self._remaining: timedelta | None = None
         self._end: datetime | None = None
-        self._listener = None
+        self._listener: Callable[[], None] | None = None
 
     @classmethod
     def from_yaml(cls, config: dict) -> Timer:
diff --git a/mypy.ini b/mypy.ini
index 2d94878ee2a..afc6c9b28af 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -1631,9 +1631,6 @@ ignore_errors = true
 [mypy-homeassistant.components.tesla.*]
 ignore_errors = true
 
-[mypy-homeassistant.components.timer.*]
-ignore_errors = true
-
 [mypy-homeassistant.components.todoist.*]
 ignore_errors = true
 
diff --git a/script/hassfest/mypy_config.py b/script/hassfest/mypy_config.py
index b761bdee919..454413624fb 100644
--- a/script/hassfest/mypy_config.py
+++ b/script/hassfest/mypy_config.py
@@ -136,7 +136,6 @@ IGNORED_MODULES: Final[list[str]] = [
     "homeassistant.components.telegram_bot.*",
     "homeassistant.components.template.*",
     "homeassistant.components.tesla.*",
-    "homeassistant.components.timer.*",
     "homeassistant.components.todoist.*",
     "homeassistant.components.toon.*",
     "homeassistant.components.tplink.*",