diff --git a/src/Attributes/Flat.php b/src/Attributes/Flat.php
new file mode 100644
index 0000000..27d73ad
--- /dev/null
+++ b/src/Attributes/Flat.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Icefox\DTO\Attributes;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_PARAMETER)]
+class Flat
+{
+}