How to center bootstrap custom-checkbox in a table header col

Maybe a dumb question but in a table head, I have to place the custom checkbox from bootstrap 4 in a col. and I can't center it.. the text-center class has no effects

here is : myfiddle

<tr class="text-white text-center bg-dark">
      <th scope="col" class="align-middle">
        <div class="custom-control custom-checkbox">
          <input type="checkbox" id="customCheck1" class="custom-control-input">
          <label for="customCheck1" class="custom-control-label"></label>
        </div>
      </th>
      <th scope="col" class="align-middle">Head-Col-1</th>
      <th scope="col" class="align-middle">Head-Col-2</th>
      <th scope="col" class="align-middle">Head-Col-3</th>
      <th scope="col" class="align-middle">Head-Col-3</th>
      <th scope="col" class="align-middle">Head-Col-3</th>
      <th scope="col" class="align-middle">Head-Col-3</th>
    </tr>

Thanks in advance