diff --git a/data/api/client-server/definitions/client_event_without_room_id.yaml b/data/api/client-server/definitions/client_event_without_room_id.yaml
index b12611a2..0988fcc2 100644
--- a/data/api/client-server/definitions/client_event_without_room_id.yaml
+++ b/data/api/client-server/definitions/client_event_without_room_id.yaml
@@ -101,9 +101,10 @@ properties:
         type: string
       prev_content:
         description: |
-          The previous `content` for this event. This field is generated
-          by the local homeserver, and is only returned if the event is a state event,
-          and the client has permission to see the previous content.
+          The `content` of the previous state event that was replaced by this event.
+          This field is generated by the local homeserver, and is only returned if
+          the event is a state event, and the client has permission to see the
+          previous event.
         x-changedInMatrixVersion:
           "1.2": |
             Previously, this field was specified at the top level of returned
@@ -113,6 +114,11 @@ properties:
             this.
         title: EventContent
         type: object
+      replaces_state:
+        description: |
+          The event ID of the state event replaced by this event. This field is generated
+          by the local homeserver, and is only returned if the event is a state event.
+        type: string
       membership:
         description: |
           The room membership of the user making the request, at the time of the event.