diff --git a/core/user.php b/core/user.php
index d1985c648..494b9930e 100644
--- a/core/user.php
+++ b/core/user.php
@@ -259,7 +259,7 @@ public function get_avatar_post_link() : ?string {
         global $database;
         $user_config = new DatabaseConfig($database, "user_config", "user_id", (string)$this->id);
         $id = $user_config->get_int("avatar_post_id");
-        if ($id === 0) {
+        if (is_null($id) || $id === 0) {
             return null;
         }
         $image = Image::by_id($id);