IE compat header

functions.php

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;
	
}