Checkbox List form behaviour

I am trying to make my partial containing form field type Checkbox List. I came across the fact that after rendering the page, the disabled attribute is removed from the input tag. Is this intended behavior?

<div class="field-checkboxlist">
    <div class="field-checkboxlist-container">
        <div class="checkbox custom-checkbox">
            <input id="my_field" type="checkbox" name="customfield" disabled="disabled">
            <label for="my_field" class="storm-icon-pseudo">Field label</label>

When I removed the field-checkboxlist wrapper class, the disabled attribute remained in place.

Yes, this is the behaviour of the checkbox list, the form field is applying its enabled state to its inner elements.

Thanx for your answer.