diff --git a/.strict-typing b/.strict-typing
index 6eeb39ceddb..9c70e27895d 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -297,6 +297,7 @@ homeassistant.components.opensky.*
 homeassistant.components.openuv.*
 homeassistant.components.otbr.*
 homeassistant.components.overkiz.*
+homeassistant.components.p1_monitor.*
 homeassistant.components.peco.*
 homeassistant.components.persistent_notification.*
 homeassistant.components.pi_hole.*
diff --git a/homeassistant/components/p1_monitor/sensor.py b/homeassistant/components/p1_monitor/sensor.py
index 17fba104c7a..587dc980e41 100644
--- a/homeassistant/components/p1_monitor/sensor.py
+++ b/homeassistant/components/p1_monitor/sensor.py
@@ -321,4 +321,4 @@ class P1MonitorSensorEntity(
         )
         if isinstance(value, str):
             return value.lower()
-        return value
+        return value  # type: ignore[no-any-return]
diff --git a/mypy.ini b/mypy.ini
index fc020a7b209..3f478afaa82 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -2731,6 +2731,16 @@ disallow_untyped_defs = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.p1_monitor.*]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+warn_return_any = true
+warn_unreachable = true
+
 [mypy-homeassistant.components.peco.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true