diff --git a/homeassistant/components/group/binary_sensor.py b/homeassistant/components/group/binary_sensor.py
index 7415ee8c60d..0c4bf89057d 100644
--- a/homeassistant/components/group/binary_sensor.py
+++ b/homeassistant/components/group/binary_sensor.py
@@ -100,7 +100,7 @@ class BinarySensorGroup(GroupEntity, BinarySensorEntity):
         name: str,
         device_class: BinarySensorDeviceClass | None,
         entity_ids: list[str],
-        mode: str | None,
+        mode: bool | None,
     ) -> None:
         """Initialize a BinarySensorGroup entity."""
         super().__init__()