Notice: Undefined index: style in panels_skinr_preprocess_index_handler() (line 354 of ..skinr/modules/panels.skinr.inc)

Brand new site, skinr installed and enabled, but not configured especially. The code in question is the second line in the function below:

function panels_skinr_preprocess_index_handler(&$vars) {
  $index = '';
  if ($vars['pane']->style['style'] == 'skinr') {
    $index =  'display-'. $vars['pane']->did .'-pane-'. $vars['pane']->pid;
  }
  return $index;
}

I guess it needs to check if it's set before comparing, to be E_NOTICE clean.