The tabs-wrapper in page.tpl.php causing failed validation

Appears the $tabs output by Drupal already creates an unordered list for the tabs. So by adding in the extra <ul class="tabs primary"> and </ul> as is done in the wrapper like below causes failed validation.

<?php if ($tabs): print '<div id="tabs-wrapper" class="clear-block"><ul class="tabs primary">'. $tabs .'</ul>'; endif; ?>

<?php if ($tabs): print '<span class="clear"></span></div>'; endif; ?>

OUTPUTS SOMETHING LIKE:

<ul class="tabs primary">
  <ul class="tabs primary">
    <li>Tab</li>
    <li>Tab</li>
  </ul>
</u>

After I removed the extra HTML shown below then all validated good.

<?php if ($tabs):
  print '<div id="tabs-wrapper" class="clear-block">'. $tabs;
endif; ?>

<?php if ($tabs): print '<span class="clear"></span></div>'; endif; ?>