diff --git a/src/Controller/Security.php b/src/Controller/Security.php
index a7a001ff9e..c9d5cc6d0d 100644
--- a/src/Controller/Security.php
+++ b/src/Controller/Security.php
@@ -135,7 +135,7 @@ class Security extends Controller
 
             try {
                 // This already checks if the nickname is being used
-                $actor = Actor::create(['nickname' => $sanitized_nickname, 'fullname' => $sanitized_nickname]);
+                $actor = Actor::create(['nickname' => $sanitized_nickname]);
                 $user  = LocalUser::create([
                     'nickname'       => $sanitized_nickname,
                     'outgoing_email' => $data['email'],
diff --git a/src/Entity/Actor.php b/src/Entity/Actor.php
index 3f4dc074e0..bc7a693377 100644
--- a/src/Entity/Actor.php
+++ b/src/Entity/Actor.php
@@ -54,7 +54,7 @@ class Actor extends Entity
     // @codeCoverageIgnoreStart
     private int $id;
     private string $nickname;
-    private string $fullname;
+    private ?string $fullname = null;
     private int $roles = 4;
     private ?string $homepage;
     private ?string $bio;
@@ -95,8 +95,11 @@ class Actor extends Entity
         return $this;
     }
 
-    public function getFullname(): string
+    public function getFullname(): ?string
     {
+        if (is_null($this->fullname)) {
+            return null;
+        }
         return $this->fullname;
     }
 
@@ -244,7 +247,7 @@ class Actor extends Entity
         return Cache::get('actor-nickname-id-' . $id, fn () => self::getById($id)->getNickname());
     }
 
-    public static function getFullnameById(int $id): string
+    public static function getFullnameById(int $id): ?string
     {
         return Cache::get('actor-fullname-id-' . $id, fn () => self::getById($id)->getFullname());
     }
diff --git a/src/Entity/Note.php b/src/Entity/Note.php
index 6c5f3578a8..9e9b6c8072 100644
--- a/src/Entity/Note.php
+++ b/src/Entity/Note.php
@@ -241,7 +241,7 @@ class Note extends Entity
         return Actor::getNicknameById($this->actor_id);
     }
 
-    public function getActorFullname(): string
+    public function getActorFullname(): ?string
     {
         return Actor::getFullnameById($this->actor_id);
     }
diff --git a/templates/cards/note/view.html.twig b/templates/cards/note/view.html.twig
index 76ec608f11..75a2aedd35 100644
--- a/templates/cards/note/view.html.twig
+++ b/templates/cards/note/view.html.twig
@@ -60,7 +60,7 @@
     {# Microformat's h-card properties indicates a face icon is a "u-logo" #}
     <a href="{{ actor_url }}" class="note-author u-url">
         <strong class="note-author-fullname">
-            {% if fullname is defined %}
+            {% if fullname is not null %}
                 {{ fullname }}
             {% else %}
                 {{ nickname }}