function bp_activity_add_notification_for_synced_blog_comment( $activity_id, $post_type_comment, $activity_args, $activity_post_object ) {
	// If activity comments are disabled for WP posts, stop now!
	if ( bp_disable_blogforum_comments() || empty( $activity_id ) ) {
		return;
	}

	// Send a notification to the blog post author.
	if ( (int) $post_type_comment->post->post_author !== (int) $activity_args['user_id'] ) {
		// Only add a notification if comment author is a registered user.
		// @todo Should we remove this restriction?
		if ( ! empty( $post_type_comment->user_id ) ) {
			bp_notifications_add_notification( array(
				'user_id'           => $post_type_comment->post->post_author,
				'item_id'           => $activity_id,
				'secondary_item_id' => $post_type_comment->user_id,
				'component_name'    => buddypress()->activity->id,
				'component_action'  => 'update_reply',
				'date_notified'     => $post_type_comment->comment_date_gmt,
				'is_new'            => 1,
			) );
		}
	}

	// Send a notification to the parent comment author for follow-up comments.
	if ( ! empty( $post_type_comment->comment_parent ) ) {
		$parent_comment = get_comment( $post_type_comment->comment_parent );

		if ( ! empty( $parent_comment->user_id ) && (int) $parent_comment->user_id !== (int) $activity_args['user_id'] ) {
			bp_notifications_add_notification( array(
				'user_id'           => $parent_comment->user_id,
				'item_id'           => $activity_id,
				'secondary_item_id' => $post_type_comment->user_id,
				'component_name'    => buddypress()->activity->id,
				'component_action'  => 'comment_reply',
				'date_notified'     => $post_type_comment->comment_date_gmt,
				'is_new'            => 1,
			) );
		}
	}
}