diff --git a/src/DataObject.php b/src/DataObject.php
index c6b05d8..cc2fcf3 100644
--- a/src/DataObject.php
+++ b/src/DataObject.php
@@ -78,9 +78,9 @@ trait DataObject
         foreach ($parameters as $parameter) {
             $parameterName = $parameter->reflection->getName();
 
-            if ($mapper = array_first($parameter->reflection->getAttributes(CastWith::class))) {
+            if ($castWith = array_first($parameter->reflection->getAttributes(CastWith::class))) {
                 $value = App::call(
-                    [App::make($mapper->newInstance()->class), 'map'],
+                    [App::make($castWith->newInstance()->class), 'cast'],
                     ['value' => $validator->getValue($parameterName)],
                 );
                 $mappedInput[$parameterName] = $value;
diff --git a/tests/Casters/CasterTest.php b/tests/Casters/CasterTest.php
new file mode 100644
index 0000000..c8e6a59
--- /dev/null
+++ b/tests/Casters/CasterTest.php
@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests;
+
+use Illuminate\Validation\ValidationException;
+use Tests\Casters\SimpleValue;
+use Tests\Casters\SimpleValueCaster;
+use Tests\Casters\WithGlobalCaster;
+use Tests\Casters\WithSpecificCaster;
+use Tests\Casters\WithoutCaster;
+
+describe('caster priority', function () {
+    beforeEach(function () {
+        config(['dto.cast' => []]);
+    });
+
+    it('uses CastWith attribute over global config caster', function () {
+        $globalCaster = function (mixed $value): SimpleValue {
+            return new SimpleValue($value['value'] * 3);
+        };
+        config(['dto.cast.' . SimpleValue::class => $globalCaster]);
+
+        $object = WithSpecificCaster::fromArray([
+            'value' => ['value' => 5],
+        ]);
+
+        expect($object->value->value)->toBe(10); // 5 * 2
+    });
+
+    it('falls back to global config caster when no CastWith attribute', function () {
+        $globalCaster = function (mixed $value): SimpleValue {
+            return new SimpleValue($value['value'] * 3);
+        };
+        config(['dto.cast.' . SimpleValue::class => $globalCaster]);
+
+        $object = WithGlobalCaster::fromArray([
+            'value' => ['value' => 5],
+        ]);
+
+        expect($object->value->value)->toBe(15); // 5 * 3
+    });
+
+    it('falls back to default construction when no caster exists', function () {
+        $object = WithoutCaster::fromArray([
+            'value' => ['value' => 5],
+        ]);
+        expect($object)->toBeInstanceOf(WithoutCaster::class);
+    });
+});
+
+describe('caster with rules', function () {
+    beforeEach(function () {
+        config(['dto.cast' => []]);
+    });
+
+    it('validates input using caster rules before casting', function () {
+        expect(fn() => WithSpecificCaster::fromArray([
+            'value' => [],
+        ]))->toThrow(ValidationException::class);
+    });
+
+    it('accepts valid input and casts correctly', function () {
+        $object = WithSpecificCaster::fromArray([
+            'value' => ['value' => 10],
+        ]);
+
+        expect($object->value->value)->toBe(20); // 10 * 2
+    });
+});
diff --git a/tests/Casters/SimpleValue.php b/tests/Casters/SimpleValue.php
new file mode 100644
index 0000000..1f08683
--- /dev/null
+++ b/tests/Casters/SimpleValue.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+class SimpleValue
+{
+    public function __construct(public readonly int $value) {}
+}
diff --git a/tests/Casters/SimpleValueCaster.php b/tests/Casters/SimpleValueCaster.php
new file mode 100644
index 0000000..05319c5
--- /dev/null
+++ b/tests/Casters/SimpleValueCaster.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+class SimpleValueCaster
+{
+    public function cast(mixed $value): SimpleValue
+    {
+        return new SimpleValue($value['value'] * 2);
+    }
+
+    public static function rules(): array
+    {
+        return [
+            'value' => ['required', 'numeric'],
+        ];
+    }
+}
diff --git a/tests/Casters/WithGlobalCaster.php b/tests/Casters/WithGlobalCaster.php
new file mode 100644
index 0000000..98b39ef
--- /dev/null
+++ b/tests/Casters/WithGlobalCaster.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+use Icefox\DTO\DataObject;
+
+readonly class WithGlobalCaster
+{
+    use DataObject;
+
+    public function __construct(
+        public SimpleValue $value,
+    ) {}
+}
diff --git a/tests/Casters/WithSpecificCaster.php b/tests/Casters/WithSpecificCaster.php
new file mode 100644
index 0000000..66041db
--- /dev/null
+++ b/tests/Casters/WithSpecificCaster.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+use Icefox\DTO\Attributes\CastWith;
+use Icefox\DTO\DataObject;
+
+readonly class WithSpecificCaster
+{
+    use DataObject;
+
+    public function __construct(
+        #[CastWith(SimpleValueCaster::class)]
+        public SimpleValue $value,
+    ) {}
+}
diff --git a/tests/Casters/WithoutCaster.php b/tests/Casters/WithoutCaster.php
new file mode 100644
index 0000000..203b0ac
--- /dev/null
+++ b/tests/Casters/WithoutCaster.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Casters;
+
+use Icefox\DTO\DataObject;
+
+readonly class WithoutCaster
+{
+    use DataObject;
+
+    public function __construct(
+        public SimpleValue $value,
+    ) {}
+}
diff --git a/tests/Classes/CarbonPeriodMapper.php b/tests/Classes/CarbonPeriodMapper.php
index 1003370..6d7d8d4 100644
--- a/tests/Classes/CarbonPeriodMapper.php
+++ b/tests/Classes/CarbonPeriodMapper.php
@@ -7,7 +7,7 @@ use Illuminate\Support\Carbon;
 
 class CarbonPeriodMapper
 {
-    public function map(mixed $value): CarbonPeriodImmutable
+    public function cast(mixed $value): CarbonPeriodImmutable
     {
         return new CarbonPeriodImmutable(Carbon::parse($value['start']), Carbon::parse($value['end']));
     }