diff --git a/api/client-server/definitions/event.yaml b/api/client-server/definitions/event.yaml
index 077036b9..a53b6af7 100644
--- a/api/client-server/definitions/event.yaml
+++ b/api/client-server/definitions/event.yaml
@@ -13,7 +13,7 @@
 # limitations under the License.
 properties:
   event_id:
-    description: The ID of this event.
+    description: The ID of this event, if applicable.
     type: string
   content:
     description: The content of this event. The fields in this object will vary depending