Edit parent variable

So I'm trying to edit the property category from the child class, but for some reasons I'm getting back an error. This I know why because there needs to be 2 arguments, but one is allready set in de parent class.

Code:

The Child

class RestaurantController extends CompanyController
{
    public function __construct(){
        parent::__construct(null, "restaurant");
        //$this->category = "restaurant";
    }
    public function getCompany($slug){
        $company = parent::index($slug);
        return view("restaurant.profile")->withInformation($company);
    }
} 

The Parent

class CompanyController extends Controller 
{
    protected $company;
    public $category;

    public function __construct(CompanyRepository $company, $category = '')
    {
        $this->category = $category;
        $this->company = $company;
    }

    public function index($slug)
    {
        $company = $this->company->getCompany($this->category, $slug);

        return compact('company');
    }
}

Now I need to know how to work a way around it.

Edit1

The error I'm getting

Type error: Argument 1 passed to App\Http\Controllers\CompanyController::__construct() must be an instance of App\Repositories\CompanyRepository, null given, called in /var/www/atify.info/dev-system/app/Http/Controllers/RestaurantController.php on line 16

edit2

This Child

class RestaurantController extends CompanyController
{
    public function getCompany($slug){
        $company = parent::index($slug);
        return view("restaurant.profile")->withInformation($company);
    }
} 

The Parent

use App\Repositories\CompanyRepository;
class CompanyController extends Controller 
{
    protected $company;

    public function __construct(CompanyRepository $company)
    {
        $this->company = $company;
    }

    public function index($slug)
    {
        $company = $this->company->getCompany($slug);

        return compact('company');
    }
}

So then I needed a category (for extra check. Otherwise you could retrieve the company inside another child with wrong functions) because I have many childs and each child have special functions

via DevJoeri