Symfony 4 не может ввести скалярное значение в службу

У меня класс ff:

namespace App\Component\Notification\RealTimeNotification;

use App\Component\Notification\NotificationInterface;

class EmailNotification implements NotificationInterface
{   
    private $logNotification;
    private $mailer;
    private $engine;

    // This will appear on From field on Email.
    private $mailerFrom;

    public function __construct(LogNotification $logNotification, \Swift_Mailer $mailer, \Twig_Environment $twig, string $from)
    {
        $this->logNotification = $logNotification;
        $this->mailer = $mailer;
        $this->twig = $twig;

        $this->mailerFrom = $mailerFrom;
    }

    public function send(array $options): void
    {   
        // Resolve options
        $this->resolveOptions($options);

        $sendTo = $options['sendTo'];
        $subject = $options['subject'];

        $template = $options['template'];
        $data = $options['data'];
        $body = $this->createTemplate($template, $data);

        $this->sendEmail($sendTo, $subject, $body);
    }

    protected function sendEmail($sendTo, $subject, $body): void
    {
        dump($this->mailerFrom);
        $message = (new \Swift_Message())
            ->setSubject($subject)
            ->setFrom($this->mailerFrom)
            ->setTo($sendTo)
            ->setBody($body, 'text/html')
        ;

        $this->mailer->send($message);
    }

    protected function createTemplate($template, $data): string
    {
        return $this->twig->render($template, $data);
    }

    protected function resolveOptions(array $options): void
    {

    }

    protected function createLog(array $email): void
    {
        $message = 'Email has been sent to: ' . $email;

        $this->logNotification->send([
            'message' => $message,
        ]);
    }
}

Я попытался вручную связать все аргументы следующим образом:

# Notification
app.log_notification:
    class: App\Component\Notification\RealTimeNotification\LogNotification

app.email_notification:
    class: App\Component\Notification\RealTimeNotification\EmailNotification
    decorates: app.log_notification
    decoration_inner_name: app.log_notification.inner
    arguments:
        $logNotification: '@app.log_notification.inner'
        $mailer: '@mailer'
        $twig: '@twig'
        $from: '%mailer_from%'

Однако когда я запускаю приложение, оно выдает исключение:

Cannot autowire service "App\Component\Notification\RealTimeNotification\EmailNotification": argument "$from" of method "__construct()" must have a type-hint or be given a value explicitly

Почему происходит это событие?

Спасибо!