diff --git a/src/CliProgram/Validation/Validators/RegexValidator.php b/src/CliProgram/Validation/Validators/RegexValidator.php
index 24ac8b7..a940c89 100644
--- a/src/CliProgram/Validation/Validators/RegexValidator.php
+++ b/src/CliProgram/Validation/Validators/RegexValidator.php
@@ -35,7 +35,7 @@ class RegexValidator implements IValidator {
      * @inheritDoc
      */
     public function validate (mixed $value): bool {
-        return preg_match($this->pattern, $value, $this->matches) === 1;
+        return preg_match($this->pattern, $value ?? '', $this->matches) === 1;
     }
 
     /**