diff --git a/src/Mapper/Object/Argument.php b/src/Mapper/Object/Argument.php
index 2dd67fe..74f1a4c 100644
--- a/src/Mapper/Object/Argument.php
+++ b/src/Mapper/Object/Argument.php
@@ -6,7 +6,16 @@ namespace CuyZ\Valinor\Mapper\Object;
 
 use CuyZ\Valinor\Definition\Attributes;
 use CuyZ\Valinor\Definition\EmptyAttributes;
+use CuyZ\Valinor\Definition\ParameterDefinition;
+use CuyZ\Valinor\Definition\PropertyDefinition;
 use CuyZ\Valinor\Type\Type;
+use CuyZ\Valinor\Type\Types\NonEmptyStringType;
+use CuyZ\Valinor\Type\Types\NullType;
+use CuyZ\Valinor\Type\Types\PositiveIntegerType;
+use CuyZ\Valinor\Type\Types\ShapedArrayElement;
+use CuyZ\Valinor\Type\Types\ShapedArrayType;
+use CuyZ\Valinor\Type\Types\StringValueType;
+use CuyZ\Valinor\Type\Types\UnionType;
 
 /** @internal */
 final class Argument
@@ -28,29 +37,48 @@ final class Argument
         $this->type = $type;
     }
 
-    public static function required(string $name, Type $type): self
+    public static function forDateTime(): self
     {
-        return new self($name, $type);
+        return new self('value', new UnionType(
+            new UnionType(PositiveIntegerType::get(), NonEmptyStringType::get()),
+            new ShapedArrayType(
+                new ShapedArrayElement(
+                    new StringValueType('datetime'),
+                    new UnionType(PositiveIntegerType::get(), NonEmptyStringType::get())
+                ),
+                new ShapedArrayElement(
+                    new StringValueType('format'),
+                    new UnionType(NullType::get(), NonEmptyStringType::get()),
+                    true
+                ),
+            )
+        ));
     }
 
-    /**
-     * @param mixed $defaultValue
-     */
-    public static function optional(string $name, Type $type, $defaultValue): self
+    public static function fromParameter(ParameterDefinition $parameter): self
     {
-        $instance = new self($name, $type);
-        $instance->defaultValue = $defaultValue;
-        $instance->isRequired = false;
+        $instance = new self($parameter->name(), $parameter->type());
+        $instance->attributes = $parameter->attributes();
+
+        if ($parameter->isOptional()) {
+            $instance->defaultValue = $parameter->defaultValue();
+            $instance->isRequired = false;
+        }
 
         return $instance;
     }
 
-    public function withAttributes(Attributes $attributes): self
+    public static function fromProperty(PropertyDefinition $property): self
     {
-        $clone = clone $this;
-        $clone->attributes = $attributes;
+        $instance = new self($property->name(), $property->type());
+        $instance->attributes = $property->attributes();
 
-        return $clone;
+        if ($property->hasDefaultValue()) {
+            $instance->defaultValue = $property->defaultValue();
+            $instance->isRequired = false;
+        }
+
+        return $instance;
     }
 
     public function name(): string
diff --git a/src/Mapper/Object/Arguments.php b/src/Mapper/Object/Arguments.php
index e6a8ef3..8b3493d 100644
--- a/src/Mapper/Object/Arguments.php
+++ b/src/Mapper/Object/Arguments.php
@@ -33,24 +33,18 @@ final class Arguments implements IteratorAggregate, Countable
 
     public static function fromParameters(Parameters $parameters): self
     {
-        return new self(...array_map(function (ParameterDefinition $parameter) {
-            $argument = $parameter->isOptional()
-                ? Argument::optional($parameter->name(), $parameter->type(), $parameter->defaultValue())
-                : Argument::required($parameter->name(), $parameter->type());
-
-            return $argument->withAttributes($parameter->attributes());
-        }, array_values(iterator_to_array($parameters)))); // @PHP8.1 array unpacking
+        return new self(...array_map(
+            fn (ParameterDefinition $parameter) => Argument::fromParameter($parameter),
+            array_values(iterator_to_array($parameters)) // @PHP8.1 array unpacking
+        ));
     }
 
     public static function fromProperties(Properties $properties): self
     {
-        return new self(...array_map(function (PropertyDefinition $property) {
-            $argument = $property->hasDefaultValue()
-                ? Argument::optional($property->name(), $property->type(), $property->defaultValue())
-                : Argument::required($property->name(), $property->type());
-
-            return $argument->withAttributes($property->attributes());
-        }, array_values(iterator_to_array($properties)))); // @PHP8.1 array unpacking
+        return new self(...array_map(
+            fn (PropertyDefinition $property) => Argument::fromProperty($property),
+            array_values(iterator_to_array($properties)) // @PHP8.1 array unpacking
+        ));
     }
 
     public function at(int $index): Argument
diff --git a/src/Mapper/Object/DateTimeObjectBuilder.php b/src/Mapper/Object/DateTimeObjectBuilder.php
index fc83ede..747ddf6 100644
--- a/src/Mapper/Object/DateTimeObjectBuilder.php
+++ b/src/Mapper/Object/DateTimeObjectBuilder.php
@@ -5,13 +5,6 @@ declare(strict_types=1);
 namespace CuyZ\Valinor\Mapper\Object;
 
 use CuyZ\Valinor\Mapper\Object\Exception\CannotParseToDateTime;
-use CuyZ\Valinor\Type\Types\NonEmptyStringType;
-use CuyZ\Valinor\Type\Types\NullType;
-use CuyZ\Valinor\Type\Types\PositiveIntegerType;
-use CuyZ\Valinor\Type\Types\ShapedArrayElement;
-use CuyZ\Valinor\Type\Types\ShapedArrayType;
-use CuyZ\Valinor\Type\Types\StringValueType;
-use CuyZ\Valinor\Type\Types\UnionType;
 use DateTime;
 use DateTimeImmutable;
 use DateTimeInterface;
@@ -44,22 +37,7 @@ final class DateTimeObjectBuilder implements ObjectBuilder
 
     public function describeArguments(): Arguments
     {
-        return $this->arguments ??= new Arguments(
-            Argument::required('value', new UnionType(
-                new UnionType(PositiveIntegerType::get(), NonEmptyStringType::get()),
-                new ShapedArrayType(
-                    new ShapedArrayElement(
-                        new StringValueType('datetime'),
-                        new UnionType(PositiveIntegerType::get(), NonEmptyStringType::get())
-                    ),
-                    new ShapedArrayElement(
-                        new StringValueType('format'),
-                        new UnionType(NullType::get(), NonEmptyStringType::get()),
-                        true
-                    ),
-                )
-            ))
-        );
+        return $this->arguments ??= new Arguments(Argument::forDateTime());
     }
 
     public function build(array $arguments): DateTimeInterface
diff --git a/tests/Fake/Definition/FakeParameterDefinition.php b/tests/Fake/Definition/FakeParameterDefinition.php
index a3d4cdd..ed82e10 100644
--- a/tests/Fake/Definition/FakeParameterDefinition.php
+++ b/tests/Fake/Definition/FakeParameterDefinition.php
@@ -28,6 +28,22 @@ final class FakeParameterDefinition
         );
     }
 
+    /**
+     * @param mixed $defaultValue
+     */
+    public static function optional(string $name, Type $type, $defaultValue): ParameterDefinition
+    {
+        return new ParameterDefinition(
+            $name,
+            $name,
+            $type,
+            true,
+            false,
+            $defaultValue,
+            new FakeAttributes()
+        );
+    }
+
     public static function fromReflection(ReflectionParameter $reflection): ParameterDefinition
     {
         $type = new FakeType();
diff --git a/tests/Unit/Utility/TypeHelperTest.php b/tests/Unit/Utility/TypeHelperTest.php
index 72811dc..f509b1c 100644
--- a/tests/Unit/Utility/TypeHelperTest.php
+++ b/tests/Unit/Utility/TypeHelperTest.php
@@ -6,6 +6,7 @@ namespace CuyZ\Valinor\Tests\Unit\Utility;
 
 use CuyZ\Valinor\Mapper\Object\Argument;
 use CuyZ\Valinor\Mapper\Object\Arguments;
+use CuyZ\Valinor\Tests\Fake\Definition\FakeParameterDefinition;
 use CuyZ\Valinor\Tests\Fake\Type\FakeObjectType;
 use CuyZ\Valinor\Tests\Fake\Type\FakeType;
 use CuyZ\Valinor\Type\Types\UnionType;
@@ -22,10 +23,10 @@ final class TypeHelperTest extends TestCase
         $typeD = FakeType::permissive();
 
         $arguments = new Arguments(
-            Argument::required('someArgument', $typeA),
-            Argument::required('someArgumentOfObject', $typeB),
-            Argument::required('someArgumentWithUnionOfObject', $typeC),
-            Argument::optional('someOptionalArgument', $typeD, 'defaultValue')
+            Argument::fromParameter(FakeParameterDefinition::new('someArgument', $typeA)),
+            Argument::fromParameter(FakeParameterDefinition::new('someArgumentOfObject', $typeB)),
+            Argument::fromParameter(FakeParameterDefinition::new('someArgumentWithUnionOfObject', $typeC)),
+            Argument::fromParameter(FakeParameterDefinition::optional('someOptionalArgument', $typeD, 'defaultValue')),
         );
 
         self::assertSame(