diff --git a/docs/specs/clients/notify/data-structures.md b/docs/specs/clients/notify/data-structures.md
index 727129d9..73a586cd 100644
--- a/docs/specs/clients/notify/data-structures.md
+++ b/docs/specs/clients/notify/data-structures.md
@@ -34,6 +34,8 @@
   icon: string | null,
   // Redirect URL for call-to-action related to notification. If null, there is no link
   url: string | null,
+  // Arbitrary custom data set by the sender of the notification
+  data: string | null,
 }
 ```
 
@@ -55,6 +57,8 @@
   icon: string,
   // Redirect URL for call-to-action related to notification. If empty, there is no link
   url: string,
+  // Arbitrary custom data set by the sender of the notification
+  data: string | null,
 }
 ```
 
diff --git a/docs/specs/servers/notify/notify-server-api.md b/docs/specs/servers/notify/notify-server-api.md
index a3c4da31..d3f77f2e 100644
--- a/docs/specs/servers/notify/notify-server-api.md
+++ b/docs/specs/servers/notify/notify-server-api.md
@@ -20,6 +20,7 @@ Body:
     "icon": string,
     "url": string,
     "type": string,
+    "data": string,
   },
   "accounts": Account[],
 }