diff --git a/homeassistant/components/systemmonitor/sensor.py b/homeassistant/components/systemmonitor/sensor.py
index 7f0866ce62e..4cfbdba4066 100644
--- a/homeassistant/components/systemmonitor/sensor.py
+++ b/homeassistant/components/systemmonitor/sensor.py
@@ -9,7 +9,7 @@ import logging
 import os
 import socket
 import sys
-from typing import Any, cast
+from typing import Any
 
 import psutil
 import voluptuous as vol
@@ -613,6 +613,6 @@ def _read_cpu_temperature() -> float | None:
             # check both name and label because some systems embed cpu# in the
             # name, which makes label not match because label adds cpu# at end.
             if _label in CPU_SENSOR_PREFIXES or name in CPU_SENSOR_PREFIXES:
-                return cast(float, round(entry.current, 1))
+                return round(entry.current, 1)
 
     return None
diff --git a/requirements_test.txt b/requirements_test.txt
index 41d81eea321..76a94c758b9 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -42,6 +42,7 @@ types-enum34==1.1.8
 types-ipaddress==1.0.8
 types-paho-mqtt==1.6.0.6
 types-pkg-resources==0.1.3
+types-psutil==5.9.5
 types-python-dateutil==2.8.19.13
 types-python-slugify==0.1.2
 types-pytz==2023.3.0.0