diff --git a/src/Attributes/Argument.php b/src/Attributes/Argument.php
index f41be69..8dc9d87 100644
--- a/src/Attributes/Argument.php
+++ b/src/Attributes/Argument.php
@@ -4,7 +4,7 @@
 
 use Attribute;
 
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER)]
 final class Argument
 {
     public function __construct()
diff --git a/src/Attributes/Description.php b/src/Attributes/Description.php
index 723e52d..9fb8a06 100644
--- a/src/Attributes/Description.php
+++ b/src/Attributes/Description.php
@@ -4,7 +4,7 @@
 
 use Attribute;
 
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER)]
 final class Description
 {
     public function __construct(
diff --git a/src/Attributes/Name.php b/src/Attributes/Name.php
index c05ca81..e119f09 100644
--- a/src/Attributes/Name.php
+++ b/src/Attributes/Name.php
@@ -4,7 +4,7 @@
 
 use Attribute;
 
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER)]
 final class Name
 {
     public function __construct(public readonly string $name)
diff --git a/src/Attributes/Option.php b/src/Attributes/Option.php
index 8feb116..7994967 100644
--- a/src/Attributes/Option.php
+++ b/src/Attributes/Option.php
@@ -4,7 +4,7 @@
 
 use Attribute;
 
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER)]
 final class Option
 {
     public function __construct()
diff --git a/src/Attributes/Shortcut.php b/src/Attributes/Shortcut.php
index 26f7850..9b9125c 100644
--- a/src/Attributes/Shortcut.php
+++ b/src/Attributes/Shortcut.php
@@ -4,7 +4,7 @@
 
 use Attribute;
 
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER)]
 final class Shortcut
 {
     public function __construct(public readonly string $shortcut)
diff --git a/src/Factory.php b/src/Factory.php
index e57f292..5caa850 100644
--- a/src/Factory.php
+++ b/src/Factory.php
@@ -5,7 +5,7 @@
 use Baethon\Symfony\Console\Input\Attributes\Argument;
 use Baethon\Symfony\Console\Input\Attributes\Option;
 use ReflectionClass;
-use ReflectionProperty;
+use ReflectionParameter;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputOption;
 
@@ -80,13 +80,16 @@ function (ParameterDefinition $parameter) {
      */
     private function collectByType(ReflectionClass $reflection, string $attribute): array
     {
+        $constructor = $reflection->getConstructor()
+            ?? throw new \InvalidArgumentException('Unable to finc constructor of '.$reflection->getName());
+
         $properties = array_filter(
-            $reflection->getProperties(ReflectionProperty::IS_PUBLIC),
-            fn (ReflectionProperty $item) => $item->getAttributes($attribute) !== [],
+            $constructor->getParameters(),
+            fn (ReflectionParameter $item) => $item->getAttributes($attribute) !== [],
         );
 
         return array_map(
-            ParameterDefinition::fromReflectionProperty(...),
+            ParameterDefinition::fromReflectionParameter(...),
             $properties,
         );
     }
diff --git a/src/ParameterDefinition.php b/src/ParameterDefinition.php
index 2d14189..5d03bbd 100644
--- a/src/ParameterDefinition.php
+++ b/src/ParameterDefinition.php
@@ -5,7 +5,7 @@
 use Baethon\Symfony\Console\Input\Attributes\Description;
 use Baethon\Symfony\Console\Input\Attributes\Name;
 use Baethon\Symfony\Console\Input\Attributes\Shortcut;
-use ReflectionProperty;
+use ReflectionParameter;
 use ReflectionType;
 
 final class ParameterDefinition
@@ -22,22 +22,24 @@ public function __construct(
         //
     }
 
-    public static function fromReflectionProperty(ReflectionProperty $property): ParameterDefinition
+    public static function fromReflectionParameter(ReflectionParameter $parameter): ParameterDefinition
     {
-        $type = $property->getType();
-        $defaultValue = $property->getDefaultValue();
+        $type = $parameter->getType();
+        $defaultValue = $parameter->isOptional()
+            ? $parameter->getDefaultValue()
+            : null;
 
         return new self(
-            name: self::findAttribute($property, Name::class)
-                ?->name ?? $property->getName(),
+            name: self::findAttribute($parameter, Name::class)
+                ?->name ?? $parameter->getName(),
             required: match (true) {
                 ! is_null($defaultValue) => false,
                 $type?->allowsNull() => false,
                 default => true,
             },
-            description: self::findAttribute($property, Description::class)
+            description: self::findAttribute($parameter, Description::class)
                 ?->description,
-            shortcut: self::findAttribute($property, Shortcut::class)
+            shortcut: self::findAttribute($parameter, Shortcut::class)
                 ?->shortcut,
             list: ($type instanceof ReflectionType && $type->getName() === 'array'),
             option: ($type instanceof ReflectionType && $type->getName() === 'bool'),
@@ -51,7 +53,7 @@ public static function fromReflectionProperty(ReflectionProperty $property): Par
      * @param  class-string<T>  $attribute
      * @return ?T
      */
-    private static function findAttribute(ReflectionProperty $property, string $attribute)
+    private static function findAttribute(ReflectionParameter $property, string $attribute)
     {
         $attributes = $property->getAttributes($attribute);
 
diff --git a/tests/Unit/FactoryTest.php b/tests/Unit/FactoryTest.php
index 073f1de..e6ac2f2 100644
--- a/tests/Unit/FactoryTest.php
+++ b/tests/Unit/FactoryTest.php
@@ -14,10 +14,12 @@
         expect($actual)->toEqual($expected);
     })->with([
         'boolean flag' => [
-            new class
+            new class(true)
             {
-                #[Option]
-                public bool $test;
+                public function __construct(
+                    #[Option]
+                    public bool $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_NONE),
@@ -25,10 +27,12 @@
         ],
 
         'string required option' => [
-            new class
+            new class('')
             {
-                #[Option]
-                public string $test;
+                public function __construct(
+                    #[Option]
+                    public string $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_REQUIRED),
@@ -36,10 +40,12 @@
         ],
 
         'string option' => [
-            new class
+            new class('')
             {
-                #[Option]
-                public ?string $test;
+                public function __construct(
+                    #[Option]
+                    public ?string $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_OPTIONAL),
@@ -47,10 +53,12 @@
         ],
 
         'array required option' => [
-            new class
+            new class([])
             {
-                #[Option]
-                public array $test;
+                public function __construct(
+                    #[Option]
+                    public array $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY),
@@ -58,10 +66,12 @@
         ],
 
         'array option' => [
-            new class
+            new class([])
             {
-                #[Option]
-                public ?array $test;
+                public function __construct(
+                    #[Option]
+                    public ?array $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_OPTIONAL | InputOption::VALUE_IS_ARRAY),
@@ -69,11 +79,13 @@
         ],
 
         'shortcut' => [
-            new class
+            new class(true)
             {
-                #[Option]
-                #[Shortcut('t')]
-                public bool $test;
+                public function __construct(
+                    #[Option]
+                    #[Shortcut('t')]
+                    public bool $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_NONE, shortcut: 't'),
@@ -81,11 +93,13 @@
         ],
 
         'description' => [
-            new class
+            new class(true)
             {
-                #[Option]
-                #[Description('Lorem ipsum')]
-                public bool $test;
+                public function __construct(
+                    #[Option]
+                    #[Description('Lorem ipsum')]
+                    public bool $test,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_NONE, description: 'Lorem ipsum'),
@@ -93,16 +107,18 @@
         ],
 
         'multiple options' => [
-            new class
+            new class(true, '', [])
             {
-                #[Option]
-                public bool $test;
+                public function __construct(
+                    #[Option]
+                    public bool $test,
 
-                #[Option]
-                public ?string $name;
+                    #[Option]
+                    public ?string $name,
 
-                #[Option]
-                public array $roles;
+                    #[Option]
+                    public array $roles,
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_NONE),
@@ -112,10 +128,12 @@
         ],
 
         'default value' => [
-            new class
+            new class('')
             {
-                #[Option]
-                public string $test = 'Lorem ipsum';
+                public function __construct(
+                    #[Option]
+                    public string $test = 'Lorem ipsum',
+                ) {}
             },
             [
                 new InputOption('test', mode: InputOption::VALUE_OPTIONAL, default: 'Lorem ipsum'),
@@ -124,12 +142,14 @@
     ]);
 
     it('doesnt pick non-options', function () {
-        $inputDto = new class
+        $inputDto = new class('', '')
         {
-            #[Argument]
-            public string $test;
+            public function __construct(
+                #[Argument]
+                public string $test,
 
-            public string $foo;
+                public string $foo,
+            ) {}
         };
 
         $actual = (new Factory)->createOptions($inputDto);
@@ -137,16 +157,18 @@
     });
 });
 
-define('InputArgument', function () {
+describe('InputArgument', function () {
     it('creates list of arguments', function ($inputDto, array $expected) {
         $actual = (new Factory)->createArguments($inputDto);
         expect($actual)->toEqual($expected);
     })->with([
         'string required option' => [
-            new class
+            new class('')
             {
-                #[Argument]
-                public string $test;
+                public function __construct(
+                    #[Argument]
+                    public string $test,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::REQUIRED),
@@ -154,10 +176,12 @@
         ],
 
         'string option' => [
-            new class
+            new class('')
             {
-                #[Argument]
-                public ?string $test;
+                public function __construct(
+                    #[Argument]
+                    public ?string $test,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::OPTIONAL),
@@ -165,10 +189,12 @@
         ],
 
         'array required option' => [
-            new class
+            new class([])
             {
-                #[Argument]
-                public array $test;
+                public function __construct(
+                    #[Argument]
+                    public array $test,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::REQUIRED | InputArgument::IS_ARRAY),
@@ -176,10 +202,12 @@
         ],
 
         'array option' => [
-            new class
+            new class([])
             {
-                #[Argument]
-                public ?array $test;
+                public function __construct(
+                    #[Argument]
+                    public ?array $test,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::OPTIONAL | InputArgument::IS_ARRAY),
@@ -187,11 +215,13 @@
         ],
 
         'description' => [
-            new class
+            new class('')
             {
-                #[Argument]
-                #[Description('Lorem ipsum')]
-                public string $test;
+                public function __construct(
+                    #[Argument]
+                    #[Description('Lorem ipsum')]
+                    public string $test,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::REQUIRED, description: 'Lorem ipsum'),
@@ -199,16 +229,18 @@
         ],
 
         'multiple options' => [
-            new class
+            new class('', '', [])
             {
-                #[Argument]
-                public string $test;
+                public function __construct(
+                    #[Argument]
+                    public string $test,
 
-                #[Argument]
-                public ?string $name;
+                    #[Argument]
+                    public ?string $name,
 
-                #[Argument]
-                public array $roles;
+                    #[Argument]
+                    public array $roles,
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::REQUIRED),
@@ -218,10 +250,12 @@
         ],
 
         'default value' => [
-            new class
+            new class('')
             {
-                #[Argument]
-                public string $test = 'Lorem ipsum';
+                public function __construct(
+                    #[Argument]
+                    public string $test = 'Lorem ipsum',
+                ) {}
             },
             [
                 new InputArgument('test', mode: InputArgument::OPTIONAL, default: 'Lorem ipsum'),
@@ -230,12 +264,14 @@
     ]);
 
     it('doesnt pick non-arguments', function () {
-        $inputDto = new class
+        $inputDto = new class('', '')
         {
-            #[Option]
-            public string $test;
+            public function __construct(
+                #[Option]
+                public string $test,
 
-            public string $bar;
+                public string $bar,
+            ) {}
         };
 
         $actual = (new Factory)->createArguments($inputDto);
diff --git a/tests/Unit/ParameterDefinitionTest.php b/tests/Unit/ParameterDefinitionTest.php
index 159a036..89f7a5a 100644
--- a/tests/Unit/ParameterDefinitionTest.php
+++ b/tests/Unit/ParameterDefinitionTest.php
@@ -6,15 +6,21 @@
 use Baethon\Symfony\Console\Input\ParameterDefinition;
 
 it('extracts definition using attributes', function ($dto, ParameterDefinition $expected, string $property = 'test') {
-    $property = (new ReflectionClass($dto))->getProperty($property);
+    $constructor = (new ReflectionClass($dto))->getConstructor();
+    $parameter = array_find(
+        $constructor->getParameters(),
+        fn (ReflectionParameter $item) => $item->getName() === $property
+    );
 
-    expect(ParameterDefinition::fromReflectionProperty($property))
+    expect(ParameterDefinition::fromReflectionParameter($parameter))
         ->toEqual($expected);
 })->with([
     'required value' => [
-        new class
+        new class('')
         {
-            public string $test;
+            public function __construct(
+                public string $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -22,9 +28,11 @@
         ),
     ],
     'optional value' => [
-        new class
+        new class(null)
         {
-            public ?string $test;
+            public function __construct(
+                public ?string $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -32,10 +40,12 @@
         ),
     ],
     'with description' => [
-        new class
+        new class('')
         {
-            #[Description('Foo')]
-            public string $test;
+            public function __construct(
+                #[Description('Foo')]
+                public string $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -44,10 +54,12 @@
         ),
     ],
     'with shortcut' => [
-        new class
+        new class('')
         {
-            #[Shortcut('f')]
-            public string $test;
+            public function __construct(
+                #[Shortcut('f')]
+                public string $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -56,10 +68,12 @@
         ),
     ],
     'with name' => [
-        new class
+        new class('')
         {
-            #[Name('foo')]
-            public string $test;
+            public function __construct(
+                #[Name('foo')]
+                public string $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'foo',
@@ -67,9 +81,11 @@
         ),
     ],
     'as array' => [
-        new class
+        new class([])
         {
-            public array $test;
+            public function __construct(
+                public array $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -78,9 +94,11 @@
         ),
     ],
     'as option' => [
-        new class
+        new class(true)
         {
-            public bool $test;
+            public function __construct(
+                public bool $test,
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',
@@ -91,7 +109,9 @@
     'default value' => [
         new class
         {
-            public string $test = 'Test';
+            public function __construct(
+                public string $test = 'Test',
+            ) {}
         },
         new ParameterDefinition(
             name: 'test',