diff --git a/.strict-typing b/.strict-typing
index 8e6e59c11d6..295a0a352e0 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -70,6 +70,7 @@ homeassistant.components.lookin.*
 homeassistant.components.mailbox.*
 homeassistant.components.media_player.*
 homeassistant.components.modbus.*
+homeassistant.components.modem_callerid.*
 homeassistant.components.mysensors.*
 homeassistant.components.nam.*
 homeassistant.components.nanoleaf.*
diff --git a/homeassistant/components/modem_callerid/config_flow.py b/homeassistant/components/modem_callerid/config_flow.py
index fd90f46d94a..da552b26beb 100644
--- a/homeassistant/components/modem_callerid/config_flow.py
+++ b/homeassistant/components/modem_callerid/config_flow.py
@@ -6,6 +6,7 @@ from typing import Any
 
 from phone_modem import DEFAULT_PORT, PhoneModem
 import serial.tools.list_ports
+from serial.tools.list_ports_common import ListPortInfo
 import voluptuous as vol
 
 from homeassistant import config_entries
@@ -20,7 +21,7 @@ _LOGGER = logging.getLogger(__name__)
 DATA_SCHEMA = vol.Schema({"name": str, "device": str})
 
 
-def _generate_unique_id(port: Any) -> str:
+def _generate_unique_id(port: ListPortInfo) -> str:
     """Generate unique id from usb attributes."""
     return f"{port.vid}:{port.pid}_{port.serial_number}_{port.manufacturer}_{port.description}"
 
diff --git a/homeassistant/components/modem_callerid/sensor.py b/homeassistant/components/modem_callerid/sensor.py
index 469e8ecb994..372f9700201 100644
--- a/homeassistant/components/modem_callerid/sensor.py
+++ b/homeassistant/components/modem_callerid/sensor.py
@@ -63,7 +63,7 @@ async def async_setup_entry(
         ]
     )
 
-    async def _async_on_hass_stop(self) -> None:
+    async def _async_on_hass_stop() -> None:
         """HA is shutting down, close modem port."""
         if hass.data[DOMAIN][entry.entry_id][DATA_KEY_API]:
             await hass.data[DOMAIN][entry.entry_id][DATA_KEY_API].close()
@@ -104,7 +104,7 @@ class ModemCalleridSensor(SensorEntity):
         await super().async_added_to_hass()
 
     @callback
-    def _async_incoming_call(self, new_state) -> None:
+    def _async_incoming_call(self, new_state: str) -> None:
         """Handle new states."""
         self._attr_extra_state_attributes = {}
         if self.api.cid_name:
diff --git a/mypy.ini b/mypy.ini
index a4740a7fedc..8114e3d39f5 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -781,6 +781,17 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.modem_callerid.*]
+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.mysensors.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true