Closing spoiler when clicking inside

The spoiler closes after pressing inside it. How to fix it?

<div class="spoiler">
    <label>
      <input type="checkbox" />
      <span class="btn">Spoiler</span>
      <div class="text">
        text<br>  
      </div>
    </label>
</div>

https://jsfiddle.net/xrgacL6w