diff --git a/homeassistant/components/plugwise/binary_sensor.py b/homeassistant/components/plugwise/binary_sensor.py
index ac7a4f796a2..956dd7f36da 100644
--- a/homeassistant/components/plugwise/binary_sensor.py
+++ b/homeassistant/components/plugwise/binary_sensor.py
@@ -152,7 +152,7 @@ class PlugwiseBinarySensorEntity(PlugwiseEntity, BinarySensorEntity):
         self._attr_unique_id = f"{device_id}-{description.key}"
 
     @property
-    def is_on(self) -> bool | None:
+    def is_on(self) -> bool:
         """Return true if the binary sensor is on."""
         return self.entity_description.value_fn(self.device["binary_sensors"])