diff --git a/custom_components/o365/const.py b/custom_components/o365/const.py
index a51e410..06fbbb2 100644
--- a/custom_components/o365/const.py
+++ b/custom_components/o365/const.py
@@ -24,6 +24,7 @@ class EventResponse(Enum):
 ATTR_EVENT_ID = "event_id"
 ATTR_FROM_DISPLAY_NAME = "from_display_name"
 ATTR_GROUP = "group"
+ATTR_ICON = "icon"
 ATTR_IS_ALL_DAY = "is_all_day"
 ATTR_IMPORTANCE = "importance"
 ATTR_LOCATION = "location"