diff --git a/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php b/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
index e596a8b6..20adc751 100644
--- a/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
+++ b/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
@@ -207,6 +207,8 @@ class ResetAutoIncrementORMPurger implements PurgerInterface, ORMPurgerInterface
             return 'ALTER TABLE '.$tableIdentifier->getQuotedName($platform).' AUTO_INCREMENT = 1;';
         }
 
+        throw new \RuntimeException("Resetting autoincrement is not supported on this platform!");
+
         //This seems to cause problems somehow
         /*if ($platform instanceof SqlitePlatform) {
             return 'DELETE FROM `sqlite_sequence` WHERE name = \''.$tableIdentifier->getQuotedName($platform).'\';';
diff --git a/tests/Validator/Constraints/NoneOfItsChildrenValidatorTest.php b/tests/Validator/Constraints/NoneOfItsChildrenValidatorTest.php
index 39eb9336..973e6cfa 100644
--- a/tests/Validator/Constraints/NoneOfItsChildrenValidatorTest.php
+++ b/tests/Validator/Constraints/NoneOfItsChildrenValidatorTest.php
@@ -57,10 +57,6 @@ class NoneOfItsChildrenValidatorTest extends ConstraintValidatorTestCase
         $this->child1_2->setName('child1_2')->setParent($this->child1);
     }
 
-    private function getDummyObjects(): array
-    {
-        $obj1 = new AttachmentType();
-    }
 
     protected function createValidator(): NoneOfItsChildrenValidator
     {