diff --git a/tests/Validator/MoneyValidatorTest.php b/tests/Validator/MoneyValidatorTest.php
index a234620..8a869cd 100644
--- a/tests/Validator/MoneyValidatorTest.php
+++ b/tests/Validator/MoneyValidatorTest.php
@@ -35,6 +35,6 @@ class MoneyValidatorTest extends ValidatorTestCase
     }
 
     private function failureDp(): array {
-        return [['122.b'], ['a.a'], ['a'], ['2.040'], ['2,a']];
+        return [['122.b'], ['a.a'], ['a'], ['2.040'], ['2,a'], ['-223']];
     }
 }