function bbp_get_topic_forum_id( $topic_id = 0 ) {
		$topic_id = bbp_get_topic_id( $topic_id );
		$forum_id = (int) get_post_field( 'post_parent', $topic_id );

		// Meta-data fallback
		if ( empty( $forum_id ) ) {
			$forum_id = (int) get_post_meta( $topic_id, '_bbp_forum_id', true );
		}

		// Filter
		if ( ! empty( $forum_id ) ) {
			$forum_id = (int) bbp_get_forum_id( $forum_id );
		}

		// Filter & return
		return (int) apply_filters( 'bbp_get_topic_forum_id', $forum_id, $topic_id );
	}