diff --git a/api/client-server/message_pagination.yaml b/api/client-server/message_pagination.yaml
index 853e0ec3..9370325b 100644
--- a/api/client-server/message_pagination.yaml
+++ b/api/client-server/message_pagination.yaml
@@ -75,6 +75,11 @@ paths:
           description: |-
             The maximum number of events to return. Default: 10.
           x-example: "3"
+        - in: query
+          type: string
+          name: filter
+          description: |-
+            A url encoded JSON RoomEventFilter to filter returned events with.
       responses:
         200:
           description: A list of messages with a new token to request more.