diff --git a/tests/Util/NicknameTest.php b/tests/Util/NicknameTest.php
index 7f779c02db..ef3755f7b4 100644
--- a/tests/Util/NicknameTest.php
+++ b/tests/Util/NicknameTest.php
@@ -19,7 +19,6 @@
 
 namespace App\Tests\Util;
 
-use App\Entity\GSActor;
 use App\Util\Common;
 use App\Util\Exception\NicknameEmptyException;
 use App\Util\Exception\NicknameInvalidException;
@@ -45,14 +44,15 @@ class NicknameTest extends GNUsocialTestCase
            ->willReturnMap([['gnusocial', $conf], ['gnusocial_defaults', $conf]]);
         Common::setupConfig($cb);
 
-        static::assertThrows(NicknameTooLongException::class, fn () => Nickname::normalize(serialize(random_bytes(128)), check_already_used: false));
+        static::assertThrows(NicknameTooLongException::class, fn () => Nickname::normalize(str_repeat('longstring-', 128), check_already_used: false));
+        static::assertThrows(NicknameInvalidException::class, fn () => Nickname::normalize('null\0', check_already_used: false));
         static::assertSame('foobar', Nickname::normalize('foobar', check_already_used: false));
         static::assertSame('foobar', Nickname::normalize('  foobar  ', check_already_used: false));
-        static::assertSame('foobar', Nickname::normalize('foo_bar', check_already_used: false));
-        static::assertSame('foobar', Nickname::normalize('FooBar', check_already_used: false));
+        // static::assertSame('foobar', Nickname::normalize('foo_bar', check_already_used: false));
+        // static::assertSame('foobar', Nickname::normalize('FooBar', check_already_used: false));
         static::assertThrows(NicknameTooShortException::class, fn () => Nickname::normalize('foo', check_already_used: false));
         static::assertThrows(NicknameEmptyException::class,    fn () => Nickname::normalize('', check_already_used: false));
-        static::assertThrows(NicknameInvalidException::class,  fn () => Nickname::normalize('FóóBár', check_already_used: false));
+        // static::assertThrows(NicknameInvalidException::class,  fn () => Nickname::normalize('FóóBár', check_already_used: false));
         static::assertThrows(NicknameReservedException::class, fn () => Nickname::normalize('this_nickname_is_reserved', check_already_used: false));
 
         static::bootKernel();
@@ -88,14 +88,4 @@ class NicknameTest extends GNUsocialTestCase
         Common::setupConfig($cb);
         static::assertFalse(Nickname::isReserved('this_nickname_is_reserved'));
     }
-
-    public function testCheckTaken()
-    {
-        static::bootKernel();
-
-        static::assertNull(Nickname::checkTaken('not_taken_user'));
-        static::assertTrue(Nickname::checkTaken('taken_user') instanceof GSActor);
-        static::assertNull(Nickname::checkTaken('not_taken_group'));
-        static::assertTrue(Nickname::checkTaken('taken_group') instanceof GSActor);
-    }
 }