diff --git a/discord.master.js b/discord.master.js
index 9a3a6b18..6b198a36 100644
--- a/discord.master.js
+++ b/discord.master.js
@@ -2192,6 +2192,13 @@ module.exports = Permissions;
 
 const { ActivityTypes, ActivityFlags } = __webpack_require__(0);
 
+/**
+ * Activity sent in a message.
+ * @typedef {Object} MessageActivity
+ * @property {string} [partyID] Id of the party represented in activity
+ * @property {number} [type] Type of activity sent
+ */
+
 /**
  * Represents a user's presence.
  */
@@ -7283,7 +7290,7 @@ class Message extends Base {
 
     /**
      * Group activity
-     * @type {?Object}
+     * @type {?MessageActivity}
      */
     this.activity = data.activity ? {
       partyID: data.activity.party_id,