diff --git a/extensions/subscriptions/extend.php b/extensions/subscriptions/extend.php
index 23d58d4ae..1a57903e5 100644
--- a/extensions/subscriptions/extend.php
+++ b/extensions/subscriptions/extend.php
@@ -7,8 +7,9 @@
  * LICENSE file that was distributed with this source code.
  */
 
-use Flarum\Api\Event\Serializing;
 use Flarum\Api\Serializer\BasicDiscussionSerializer;
+use Flarum\Api\Serializer\DiscussionSerializer;
+use Flarum\Discussion\Discussion;
 use Flarum\Discussion\Event\Saving;
 use Flarum\Discussion\Event\Searching;
 use Flarum\Event\ConfigureDiscussionGambits;
@@ -21,7 +22,6 @@ use Flarum\Post\Event\Restored;
 use Flarum\Subscriptions\Gambit\SubscriptionGambit;
 use Flarum\Subscriptions\Listener;
 use Flarum\Subscriptions\Notification\NewPostBlueprint;
-use Illuminate\Contracts\Events\Dispatcher;
 
 return [
     (new Extend\Frontend('forum'))
@@ -37,23 +37,25 @@ return [
     (new Extend\Notification())
         ->type(NewPostBlueprint::class, BasicDiscussionSerializer::class, ['alert', 'email']),
 
-    function (Dispatcher $events) {
-        $events->listen(Serializing::class, Listener\AddDiscussionSubscriptionAttribute::class);
-        $events->listen(Saving::class, Listener\SaveSubscriptionToDatabase::class);
+    (new Extend\ApiSerializer(DiscussionSerializer::class))
+        ->attribute('subscription', function (DiscussionSerializer $serializer, Discussion $discussion) {
+            if ($state = $discussion->state) {
+                return $state->subscription ?: false;
+            }
+        }),
 
-        $events->listen(ConfigureDiscussionGambits::class, function (ConfigureDiscussionGambits $event) {
+    (new Extend\Event())
+        ->listen(Saving::class, Listener\SaveSubscriptionToDatabase::class)
+        ->listen(ConfigureDiscussionGambits::class, function (ConfigureDiscussionGambits $event) {
             $event->gambits->add(SubscriptionGambit::class);
-        });
-        $events->listen(Searching::class, Listener\FilterDiscussionListBySubscription::class);
-
-        $events->listen(Posted::class, Listener\SendNotificationWhenReplyIsPosted::class);
-        $events->listen(Hidden::class, Listener\DeleteNotificationWhenPostIsHiddenOrDeleted::class);
-        $events->listen(Restored::class, Listener\RestoreNotificationWhenPostIsRestored::class);
-        $events->listen(Deleted::class, Listener\DeleteNotificationWhenPostIsHiddenOrDeleted::class);
-
-        $events->listen(ConfigureUserPreferences::class, function (ConfigureUserPreferences $event) {
+        })
+        ->listen(Searching::class, Listener\FilterDiscussionListBySubscription::class)
+        ->listen(Posted::class, Listener\SendNotificationWhenReplyIsPosted::class)
+        ->listen(Hidden::class, Listener\DeleteNotificationWhenPostIsHiddenOrDeleted::class)
+        ->listen(Restored::class, Listener\RestoreNotificationWhenPostIsRestored::class)
+        ->listen(Deleted::class, Listener\DeleteNotificationWhenPostIsHiddenOrDeleted::class)
+        ->listen(ConfigureUserPreferences::class, function (ConfigureUserPreferences $event) {
             $event->add('followAfterReply', 'boolval', false);
-        });
-        $events->listen(Posted::class, Listener\FollowAfterReply::class);
-    }
+        })
+        ->listen(Posted::class, Listener\FollowAfterReply::class),
 ];
diff --git a/extensions/subscriptions/src/Listener/AddDiscussionSubscriptionAttribute.php b/extensions/subscriptions/src/Listener/AddDiscussionSubscriptionAttribute.php
deleted file mode 100755
index 6c4773e76..000000000
--- a/extensions/subscriptions/src/Listener/AddDiscussionSubscriptionAttribute.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-/*
- * This file is part of Flarum.
- *
- * For detailed copyright and license information, please view the
- * LICENSE file that was distributed with this source code.
- */
-
-namespace Flarum\Subscriptions\Listener;
-
-use Flarum\Api\Event\Serializing;
-use Flarum\Api\Serializer\DiscussionSerializer;
-
-class AddDiscussionSubscriptionAttribute
-{
-    public function handle(Serializing $event)
-    {
-        if ($event->isSerializer(DiscussionSerializer::class)
-            && ($state = $event->model->state)) {
-            $event->attributes['subscription'] = $state->subscription ?: false;
-        }
-    }
-}