diff --git a/Classes/Command/RepositoryCommand.php b/Classes/Command/RepositoryCommand.php
index f7cfde2..d8d5268 100644
--- a/Classes/Command/RepositoryCommand.php
+++ b/Classes/Command/RepositoryCommand.php
@@ -19,6 +19,7 @@
 use FriendsOfTYPO3\Kickstarter\Traits\CreatorInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\ExtensionInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\TryToCorrectClassNameTrait;
+use FriendsOfTYPO3\Kickstarter\Validator\PhpClassNameValidator;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -34,6 +35,7 @@ class RepositoryCommand extends Command
     public function __construct(
         private readonly RepositoryCreatorService $repositoryCreatorService,
         private readonly QuestionCollection $questionCollection,
+        private readonly PhpClassNameValidator $classNameValidator,
     ) {
         parent::__construct();
     }
@@ -96,13 +98,8 @@ private function askForRepositoryClassName(SymfonyStyle $io): string
             if ($repositoryClassName === '') {
                 $io->error('Class name can not be empty.');
                 $validRepositoryClassName = false;
-            } elseif (preg_match('/^\d/', $repositoryClassName)) {
-                $io->error('Class name should not start with a number.');
-                $defaultRepositoryClassName = $this->tryToCorrectClassName($repositoryClassName, 'Repository');
-                $validRepositoryClassName = false;
-            } elseif (preg_match('/[^a-zA-Z0-9]/', $repositoryClassName)) {
-                $io->error('Class name contains invalid chars. Please provide just letters and numbers.');
-                $defaultRepositoryClassName = $this->tryToCorrectClassName($repositoryClassName, 'Repository');
+            } elseif (!$this->classNameValidator->validate($repositoryClassName)) {
+                $io->error('Class name is not a valid php class name.');
                 $validRepositoryClassName = false;
             } elseif (preg_match('/^[A-Z][a-zA-Z0-9]+$/', $repositoryClassName) === 0) {
                 $io->error('Action must be written in UpperCamelCase like "CarRepository".');
diff --git a/Classes/Command/TypeConverterCommand.php b/Classes/Command/TypeConverterCommand.php
index 5677bf8..777b0ac 100644
--- a/Classes/Command/TypeConverterCommand.php
+++ b/Classes/Command/TypeConverterCommand.php
@@ -19,6 +19,7 @@
 use FriendsOfTYPO3\Kickstarter\Traits\CreatorInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\ExtensionInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\TryToCorrectClassNameTrait;
+use FriendsOfTYPO3\Kickstarter\Validator\PhpClassNameValidator;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -34,6 +35,7 @@ class TypeConverterCommand extends Command
     public function __construct(
         private readonly TypeConverterCreatorService $typeConverterCreatorService,
         private readonly QuestionCollection $questionCollection,
+        private readonly PhpClassNameValidator $classNameValidator,
     ) {
         parent::__construct();
     }
@@ -96,13 +98,11 @@ private function askForTypeConverterClassName(SymfonyStyle $io): string
                 $defaultTypeConverterClassName,
             );
 
-            if (preg_match('/^\d/', $typeConverterClassName)) {
-                $io->error('Class name should not start with a number.');
-                $defaultTypeConverterClassName = $this->tryToCorrectClassName($typeConverterClassName, 'Converter');
+            if ($typeConverterClassName === '') {
+                $io->error('Class name can not be empty.');
                 $validTypeConverterClassName = false;
-            } elseif (preg_match('/[^a-zA-Z0-9]/', $typeConverterClassName)) {
-                $io->error('Class name contains invalid chars. Please provide just letters and numbers.');
-                $defaultTypeConverterClassName = $this->tryToCorrectClassName($typeConverterClassName, 'Converter');
+            } elseif (!$this->classNameValidator->validate($typeConverterClassName)) {
+                $io->error('Class name is not a valid php class name.');
                 $validTypeConverterClassName = false;
             } elseif (preg_match('/^[A-Z][a-zA-Z0-9]+$/', $typeConverterClassName) === 0) {
                 $io->error('Class name must be written in UpperCamelCase like "FileUploadConverter".');
diff --git a/Classes/Command/UpgradeWizardCommand.php b/Classes/Command/UpgradeWizardCommand.php
index d3c15b1..ec9532c 100644
--- a/Classes/Command/UpgradeWizardCommand.php
+++ b/Classes/Command/UpgradeWizardCommand.php
@@ -19,6 +19,7 @@
 use FriendsOfTYPO3\Kickstarter\Traits\CreatorInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\ExtensionInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\TryToCorrectClassNameTrait;
+use FriendsOfTYPO3\Kickstarter\Validator\PhpClassNameValidator;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -34,6 +35,7 @@ class UpgradeWizardCommand extends Command
     public function __construct(
         private readonly UpgradeWizardCreatorService $upgradeWizardCreatorService,
         private readonly QuestionCollection $questionCollection,
+        private readonly PhpClassNameValidator $classNameValidator,
     ) {
         parent::__construct();
     }
@@ -93,13 +95,11 @@ private function askForUpgradeWizardClassName(SymfonyStyle $io): string
                 $defaultUpgradeWizardClassName,
             );
 
-            if (preg_match('/^\d/', $upgradeWizardClassName)) {
-                $io->error('Class name should not start with a number.');
-                $defaultUpgradeWizardClassName = $this->tryToCorrectClassName($upgradeWizardClassName, 'Upgrade');
+            if ($upgradeWizardClassName === '') {
+                $io->error('Class name can not be empty.');
                 $validUpgradeWizardClassName = false;
-            } elseif (preg_match('/[^a-zA-Z0-9]/', $upgradeWizardClassName)) {
-                $io->error('Class name contains invalid chars. Please provide just letters and numbers.');
-                $defaultUpgradeWizardClassName = $this->tryToCorrectClassName($upgradeWizardClassName, 'Upgrade');
+            } elseif (!$this->classNameValidator->validate($upgradeWizardClassName)) {
+                $io->error('Class name is not a valid php class name.');
                 $validUpgradeWizardClassName = false;
             } elseif (preg_match('/^[A-Z][a-zA-Z0-9]+$/', $upgradeWizardClassName) === 0) {
                 $io->error('Action must be written in UpperCamelCase like "CorrectPluginUpgrade".');
diff --git a/Classes/Command/ValidatorCommand.php b/Classes/Command/ValidatorCommand.php
index 0e5532b..7dc34f2 100644
--- a/Classes/Command/ValidatorCommand.php
+++ b/Classes/Command/ValidatorCommand.php
@@ -22,6 +22,7 @@
 use FriendsOfTYPO3\Kickstarter\Traits\CreatorInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\ExtensionInformationTrait;
 use FriendsOfTYPO3\Kickstarter\Traits\TryToCorrectClassNameTrait;
+use FriendsOfTYPO3\Kickstarter\Validator\PhpClassNameValidator;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -38,6 +39,7 @@ class ValidatorCommand extends Command
     public function __construct(
         private readonly ValidatorCreatorService $validatorCreatorService,
         private readonly QuestionCollection $questionCollection,
+        private readonly PhpClassNameValidator $classNameValidator,
     ) {
         parent::__construct();
     }
@@ -122,13 +124,11 @@ private function askForValidatorName(SymfonyStyle $io): string
                 $defaultName,
             );
 
-            if (preg_match('/^\d/', $name)) {
-                $io->error('Validator name should not start with a number.');
-                $defaultName = $this->tryToCorrectClassName($name, 'Validator');
+            if ($name === '') {
+                $io->error('Class name can not be empty.');
                 $validValidatorName = false;
-            } elseif (preg_match('/[^a-zA-Z0-9]/', $name)) {
-                $io->error('Validator name contains invalid chars. Please provide just letters and numbers.');
-                $defaultName = $this->tryToCorrectClassName($name, 'Validator');
+            } elseif (!$this->classNameValidator->validate($name)) {
+                $io->error('Class name is not a valid php class name.');
                 $validValidatorName = false;
             } elseif (preg_match('/^[a-z0-9]+$/', $name)) {
                 $io->error('Validator must be written in UpperCamelCase like BlogExampleValidator.');
diff --git a/Classes/Validator/PhpClassNameValidator.php b/Classes/Validator/PhpClassNameValidator.php
new file mode 100644
index 0000000..413d4a5
--- /dev/null
+++ b/Classes/Validator/PhpClassNameValidator.php
@@ -0,0 +1,112 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the package friendsoftypo3/kickstarter.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace FriendsOfTYPO3\Kickstarter\Validator;
+
+final readonly class PhpClassNameValidator
+{
+    /**
+     * List of reserved keywords in PHP that cannot be used as class names (case-insensitive).
+     * This list is a common compilation of hard-reserved words.
+     * Some of these are context-sensitive keywords in newer PHP versions but are often
+     * treated as reserved in the context of class/interface/trait names for compatibility
+     * or future-proofing.
+     * Note: 'void', 'iterable', 'object', etc., are not reserved as class names
+     * in older PHP versions but might be in stricter contexts.
+     *
+     * @var array<string>
+     */
+    private const RESERVED_KEYWORDS = [
+        '__halt_compiler',
+        'abstract',
+        'and',
+        'array',
+        'as',
+        'break',
+        'callable',
+        'case',
+        'catch',
+        'class',
+        'clone',
+        'const',
+        'continue',
+        'declare',
+        'default',
+        'die',
+        'do',
+        'echo',
+        'else',
+        'elseif',
+        'empty',
+        'enddeclare',
+        'endfor',
+        'endforeach',
+        'endif',
+        'endswitch',
+        'endwhile',
+        'enum', // Added for PHP 8.1+
+        'exit',
+        'extends',
+        'final',
+        'finally',
+        'fn', // Added for PHP 7.4+
+        'for',
+        'foreach',
+        'function',
+        'global',
+        'goto',
+        'if',
+        'implements',
+        'include',
+        'include_once',
+        'instanceof',
+        'insteadof',
+        'interface',
+        'isset',
+        'list',
+        'match', // Added for PHP 8.0+
+        'namespace',
+        'new',
+        'or',
+        'parent',
+        'print',
+        'private',
+        'protected',
+        'public',
+        'readonly', // Added for PHP 8.1+
+        'require',
+        'require_once',
+        'return',
+        'self',
+        'static',
+        'switch',
+        'throw',
+        'trait',
+        'try',
+        'unset',
+        'use',
+        'var',
+        'while',
+        'xor',
+        'yield',
+    ];
+
+    public function validate(string $className): bool
+    {
+        // regex from https://www.php.net/manual/en/language.oop5.basic.php
+        $isValidFormat = (bool)preg_match('/^[a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*$/', $className);
+        if (!$isValidFormat) {
+            return false;
+        }
+
+        return !in_array(strtolower($className), self::RESERVED_KEYWORDS, true);
+    }
+}