diff --git a/src/Util/Functional.php b/src/Util/Exception/NicknameTooShortException.php
similarity index 50%
rename from src/Util/Functional.php
rename to src/Util/Exception/NicknameTooShortException.php
index 0cc75bcc51..d9756569ef 100644
--- a/src/Util/Functional.php
+++ b/src/Util/Exception/NicknameTooShortException.php
@@ -1,6 +1,7 @@
 <?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
@@ -15,21 +16,39 @@
 //
 // 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/>.
+
 // }}}
 
 /**
- * Functional utilities
+ * Nickname too long exception
  *
+ * @category  Exception
  * @package   GNUsocial
- * @category  Util
+ *
+ * @author    Zach Copley <zach@status.net>
+ * @copyright 2010 StatusNet Inc.
+ * @author    Brion Vibber <brion@pobox.com>
+ * @author    Mikael Nordfeldth <mmn@hethane.se>
+ * @author    Nym Coy <nymcoy@gmail.com>
+ * @copyright 2009-2014 Free Software Foundation, Inc http://www.fsf.org
+ * @auuthor   Daniel Supernault <danielsupernault@gmail.com>
+ * @auuthor   Diogo Cordeiro <diogo@fc.up.pt>
  *
  * @author    Hugo Sales <hugo@hsal.es>
- * @copyright 2020-2021 Free Software Foundation, Inc http://www.fsf.org
+ * @copyright 2018-2021 Free Software Foundation, Inc http://www.fsf.org
  * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
  */
 
-namespace App\Util;
+namespace App\Util\Exception;
 
-abstract class Functional
+use function App\Core\I18n\_m;
+use App\Util\Nickname;
+
+class NicknameTooLongException extends NicknameInvalidException
 {
+    protected function defaultMessage(): string
+    {
+        // TRANS: Validation error in form for registration, profile and group settings, etc.
+        return _m('Nickname cannot be more than # character long.', ['count' => Nickname::MAX_LEN]);
+    }
 }
diff --git a/tests/Util/Form/ActorArrayTransformer/ActorArrayTransformerTest.php b/tests/Util/Form/ActorArrayTransformerTest.php
similarity index 99%
rename from tests/Util/Form/ActorArrayTransformer/ActorArrayTransformerTest.php
rename to tests/Util/Form/ActorArrayTransformerTest.php
index 6f8714d816..049c9598cd 100644
--- a/tests/Util/Form/ActorArrayTransformer/ActorArrayTransformerTest.php
+++ b/tests/Util/Form/ActorArrayTransformerTest.php
@@ -1,4 +1,5 @@
 <?php
+
 // {{{ License
 // This file is part of GNU social - https://www.gnu.org/software/social
 //
@@ -36,6 +37,7 @@ class ActorArrayTransformerTest extends WebTestCase
 
         static::assertSame('user1 user2 user3', (new ActorArrayTransformer)->transform($testArr));
     }
+
     public function testReverseTransform()
     {
         $testString = '';