diff --git a/framework/core/js/forum/src/ForumApp.js b/framework/core/js/forum/src/ForumApp.js
index 4de2b40a5..9e7edd397 100644
--- a/framework/core/js/forum/src/ForumApp.js
+++ b/framework/core/js/forum/src/ForumApp.js
@@ -45,13 +45,6 @@ export default class ForumApp extends App {
      */
     this.postComponents = {};
 
-    /**
-     * A map of activity types to their components.
-     *
-     * @type {Object}
-     */
-    this.activityComponents = {};
-
     /**
      * A map of notification types to their components.
      *