How to wrap long word inside container using Twitter Bootstrap 3?

This is my html:

<div class="container-fluid">
    <div class="row post img-rounded">
        <span>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
    </div>
</div>

The issue is, the end user selects what is inside the span. If the content inside the span is a very long word, then a horizontal scroll bar appears and the word extends outside of the div. Is there a non-hacky (possibly Twitter Bootstrap 3) way of basically wrapping the word so that it does not extend outside of the div, causing a horizontal scrollbar?

If not, what's the best way to solve the issue?