diff --git a/models/Category.php b/models/Category.php
index 7de1ccc..2e42d65 100644
--- a/models/Category.php
+++ b/models/Category.php
@@ -31,7 +31,7 @@ class Category extends Model
 		if (App::$user && App::$user->isAdmin == 1) {
 			return $this->getAll(array('order' => 'ord ASC', 'asArray' => true));
 		} else {
-			return $this->getAll(array('where' => '`id` NOT IN ('.  implode(',', $this->paidIds).')',  'order' => 'ord ASC', 'asArray' => true));
+			return $this->getAll(array('where' => '`id` NOT IN ('.  implode(',', self::$paidIds).')',  'order' => 'ord ASC', 'asArray' => true));
 		}
 	}