function bbp_user_add_role_on_invite( $user_id = '', $role = '', $newuser_key = '' ) {

	// Posted role
	$forum_role = isset( $_POST['bbp-forums-role'] )
		? sanitize_key( $_POST['bbp-forums-role'] )
		: bbp_get_default_role();

	// Role keys
	$roles = array_keys( bbp_get_dynamic_roles() );

	// Bail if posted role is not in dynamic roles
	if ( empty( $forum_role ) || ! in_array( $forum_role, $roles, true ) ) {
		return;
	}

	// Option key
	$option_key = 'new_user_' . $newuser_key;

	// Get the user option
	$user_option = get_option( $option_key, array() );

	// Add the new role
	$user_option['bbp_new_role'] = $forum_role;

	// Update the invitation
	update_option( $option_key, $user_option );
}