function ms_file_constants() {
	/**
	 * Optional support for X-Sendfile header
	 *
	 * @since 3.0.0
	 */
	if ( ! defined( 'WPMU_SENDFILE' ) ) {
		define( 'WPMU_SENDFILE', false );
	}

	/**
	 * Optional support for X-Accel-Redirect header
	 *
	 * @since 3.0.0
	 */
	if ( ! defined( 'WPMU_ACCEL_REDIRECT' ) ) {
		define( 'WPMU_ACCEL_REDIRECT', false );
	}
}