Fatal error: Cannot use ::class with dynamic class name

[Vladzimir]

<?php

use Leaf\UI;
use Leaf\UI\Component;

require __DIR__ . '/vendor/autoload.php';

class Counter extends Component
{
  public $count = 0;
  public $key = 'Counter';

  public function increment()
  {
    $this->count++;
  }

  public function decrement()
  {
    $this->count--;
  }

  public function render()
  {
    return UI::view('view.html');
  }
}

UI::render(new Counter());

Fatal error: Cannot use ::class with dynamic class name in vendor\leafs\ui\src\UI.php on line 46