Popover selector option not working

When using the selector popover option, nothing actually happens:

<div id="some-div">
  <span>Some stuff</span>
</div>

<div id="popover-element">
  <p>This is the popover text</p>
  <p>But it also gets complicated...</p>
</div>

and:

$(document).ready(function() {
  $('#some-div').popover({
    selector: $('#popover-element') // also tried just '#popover-element', same result
  });
});

If I revert back to just a data-content:

<div id="some-div" data-content="hai">

then things work fine, but I need more than just text in the popover.