diff --git a/homeassistant/components/supervisord/sensor.py b/homeassistant/components/supervisord/sensor.py
index 5db8680f1c9..2f443f0d25f 100644
--- a/homeassistant/components/supervisord/sensor.py
+++ b/homeassistant/components/supervisord/sensor.py
@@ -1,4 +1,6 @@
 """Sensor for Supervisord process status."""
+from __future__ import annotations
+
 import logging
 import xmlrpc.client
 
@@ -6,7 +8,10 @@ import voluptuous as vol
 
 from homeassistant.components.sensor import PLATFORM_SCHEMA, SensorEntity
 from homeassistant.const import CONF_URL
+from homeassistant.core import HomeAssistant
 import homeassistant.helpers.config_validation as cv
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
+from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -20,15 +25,22 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
 )
 
 
-def setup_platform(hass, config, add_entities, discovery_info=None):
+def setup_platform(
+    hass: HomeAssistant,
+    config: ConfigType,
+    add_entities: AddEntitiesCallback,
+    discovery_info: DiscoveryInfoType | None = None,
+) -> None:
     """Set up the Supervisord platform."""
-    url = config.get(CONF_URL)
+    url = config[CONF_URL]
     try:
         supervisor_server = xmlrpc.client.ServerProxy(url)
-        processes = supervisor_server.supervisor.getAllProcessInfo()
+        # See this link to explain the type ignore:
+        # http://supervisord.org/api.html#supervisor.rpcinterface.SupervisorNamespaceRPCInterface.getAllProcessInfo
+        processes: list[dict] = supervisor_server.supervisor.getAllProcessInfo()  # type: ignore[assignment]
     except ConnectionRefusedError:
         _LOGGER.error("Could not connect to Supervisord")
-        return False
+        return
 
     add_entities(
         [SupervisorProcessSensor(info, supervisor_server) for info in processes], True