diff --git a/proposals/2881-message-attachments.md b/proposals/2881-message-attachments.md
index 07a2b198d..c8a4baa67 100644
--- a/proposals/2881-message-attachments.md
+++ b/proposals/2881-message-attachments.md
@@ -199,7 +199,7 @@ This way will give less "spam" for room, because when user sends message with 20
       "rel_type": "m.attachment_to",
       "event_id": "$id_of_main_message"
     }
-  ]
+  ],
   "url": "mxc://example.com/KUAQOesGECkQTgdtedkftISg"
 },
 ```