diff --git a/plugins/Favourite/Controller/Favourite.php b/plugins/Favourite/Controller/Favourite.php
index a7b8e0b5ee..b842bc1f8f 100644
--- a/plugins/Favourite/Controller/Favourite.php
+++ b/plugins/Favourite/Controller/Favourite.php
@@ -35,11 +35,11 @@ class Favourite
                             'where f.gsactor_id = :id ' .
                             'order by f.created DESC', ['id' => $actor_id]);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$note_out]);
 
         return [
             '_template' => 'network/public.html.twig',
-            'notes'     => $notes,
+            'notes'     => $notes_out,
         ];
     }
 
@@ -62,7 +62,7 @@ class Favourite
                             'order by f.created DESC' ,
                             ['id' => $actor_id]);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$notes_out]);
 
         return [
             '_template' => 'network/reversefavs.html.twig',
diff --git a/plugins/TreeNotes/TreeNotes.php b/plugins/TreeNotes/TreeNotes.php
index 1d8c1aba93..249a36b1d7 100644
--- a/plugins/TreeNotes/TreeNotes.php
+++ b/plugins/TreeNotes/TreeNotes.php
@@ -27,10 +27,10 @@ class TreeNotes extends Plugin
     /**
      * Format the given $notes_in_trees_out in a list of reply trees
      */
-    public function onFormatNoteList(array &$notes_in_trees_out)
+    public function onFormatNoteList(array $notes_in, ?array &$notes_out)
     {
-        $roots              = array_filter($notes_in_trees_out, function (Note $note) { return $note->getReplyTo() == null; }, ARRAY_FILTER_USE_BOTH);
-        $notes_in_trees_out = $this->build_tree($roots, $notes_in_trees_out);
+        $roots     = array_filter($notes_in, function (Note $note) { return $note->getReplyTo() == null; });
+        $notes_out = $this->build_tree($roots, $notes_in);
     }
 
     private function build_tree(array $parents, array $notes)
@@ -44,7 +44,7 @@ class TreeNotes extends Plugin
 
     private function build_subtree(Note $parent, array $notes)
     {
-        $children = array_filter($notes, function (Note $n) use ($parent) { return $parent->getId() == $n->getReplyTo(); }, ARRAY_FILTER_USE_BOTH);
+        $children = array_filter($notes, function (Note $n) use ($parent) { return $parent->getId() == $n->getReplyTo(); });
         return ['note' => $parent, 'replies' => $this->build_tree($children, $notes)];
     }
 }
diff --git a/src/Controller/Network.php b/src/Controller/Network.php
index e16c0fa34b..7f4adecccc 100644
--- a/src/Controller/Network.php
+++ b/src/Controller/Network.php
@@ -56,11 +56,11 @@ class Network extends Controller
     {
         $notes = Note::getAllNotes($this->instance_scope);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$notes_out]);
 
         return [
             '_template' => 'network/public.html.twig',
-            'notes'     => $notes,
+            'notes'     => $notes_out,
         ];
     }
 
@@ -98,11 +98,11 @@ class Network extends Controller
 END;
         $notes = DB::sql($query, ['note' => 'App\Entity\Note'], ['target_actor_id' => $target->getId()]);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$notes_out]);
 
         return [
             '_template' => 'network/public.html.twig',
-            'notes'     => $notes,
+            'notes'     => $notes_out,
         ];
     }
 
@@ -110,11 +110,11 @@ END;
     {
         $notes = Note::getAllNotes($this->public_scope);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$notes_out]);
 
         return [
             '_template' => 'network/public.html.twig',
-            'notes'     => $notes,
+            'notes'     => $notes_out,
         ];
     }
 
@@ -125,11 +125,11 @@ END;
                          'where n.reply_to is not null and n.gsactor_id = :id ' .
                          'order by n.created DESC', ['id' => $actor_id]);
 
-        Event::handle('FormatNoteList', [&$notes]);
+        Event::handle('FormatNoteList', [$notes, &$notes_out]);
 
         return [
             '_template' => 'network/public.html.twig',
-            'notes'     => $notes,
+            'notes'     => $notes_out,
         ];
     }
 }
diff --git a/tests/Core/ControllerTest.php b/tests/Core/ControllerTest.php
new file mode 100644
index 0000000000..1d34550a76
--- /dev/null
+++ b/tests/Core/ControllerTest.php
@@ -0,0 +1,43 @@
+<?php
+
+// {{{ License
+
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GNU social is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+
+// }}}
+
+namespace App\Tests\Core;
+
+use App\Util\GNUsocialTestCase;
+use Jchook\AssertThrows\AssertThrows;
+
+class ControllerTest extends GNUsocialTestCase
+{
+    use AssertThrows;
+
+    public function testJSONRequest()
+    {
+        // `server` will populate $_SERVER on the other side
+        $client = static::createClient(options: [], server: ['HTTP_ACCEPT' => 'application/json']);
+        $client->request('GET', '/main/all');
+        $this->assertResponseIsSuccessful();
+        $response = $client->getResponse();
+        static::assertTrue($response->headers->contains('Content-Type', 'application/json'));
+        static::assertJson($response->getContent());
+        $json = json_decode($response->getContent(), associative: true);
+        dd($json);
+    }
+}