CSS style checkbox label if is inside

Question

I have the following markup:

<label>
    <input type="checkbox">
    One
</label>
<label>
    <input type="checkbox">
    Two
</label>

I would like to change the label background for the checkbox checked state.

The issue is that the input is inside the label, so I can't use the good old input[type=checkbox] + label {}

I cannot change this markup, so I cannot easily just add <span> tag around the text.

Is there a way to change the label on :checked state?

Here is my work in progress fiddle: https://jsfiddle.net/kgpnbdzy/2/