diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index 8b00fb97d1..412f38cf3a 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -2537,8 +2537,9 @@ paths:
                                 subject:
                                   type: string
                                   description: |
-                                    Only present if this event moved messages to a different
-                                    topic.
+                                    Only present if this event moved messages to a different topic;
+                                    this field will not be present when moving messages to the same
+                                    topic name in a different channel.
 
                                     The post-edit topic for all of the messages with IDs in
                                     `message_ids`.
@@ -2557,8 +2558,9 @@ paths:
                                         description: |
                                           The expanded target url which the link points to.
                                   description: |
-                                    Only present if this event moved messages to a different
-                                    topic.
+                                    Only present if this event moved messages to a different topic;
+                                    this field will not be present when moving messages to the same
+                                    topic name in a different channel.
 
                                     Data on any links to be included in the `topic`
                                     line (these are generated by