IE compat header
add_filter( 'wp_headers', 'add_ie_compatibility_header' );
/**
* Disable IE compatibilty view modus.
*
* Not 100% guaranteed to have affect.
*
* @since 1.0.0
*/
function add_ie_compatibility_header( $headers ) {
$headers['X-UA-Compatible'] = 'IE=edge';
return $headers;
}