public function migrate_from_sp_events() {
		$legacy_option = get_option( 'sp_events_calendar_options' );
		if ( empty( $legacy_option ) ) {
			return;
		}

		$new_option = get_option( Tribe__Events__Main::OPTIONNAME );
		if ( ! $new_option ) {
			update_option( Tribe__Events__Main::OPTIONNAME, $legacy_option );
		}
		delete_option( 'sp_events_calendar_options' );

		/** @var wpdb $wpdb */
		global $wpdb;
		$count = $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->posts} WHERE post_type IN ( 'sp_events', 'sp_venue', 'sp_organizer' )" );
		if ( ! $count ) {
			return;
		}

		// update post type names
		$wpdb->update( $wpdb->posts, array( 'post_type' => Tribe__Events__Main::POSTTYPE ), array( 'post_type' => 'sp_events' ) );
		$wpdb->update( $wpdb->posts, array( 'post_type' => Tribe__Events__Main::VENUE_POST_TYPE ), array( 'post_type' => 'sp_venue' ) );
		$wpdb->update( $wpdb->posts, array( 'post_type' => Tribe__Events__Main::ORGANIZER_POST_TYPE ), array( 'post_type' => 'sp_organizer' ) );

		// update taxonomy names
		$wpdb->update( $wpdb->term_taxonomy, array( 'taxonomy' => Tribe__Events__Main::TAXONOMY ), array( 'taxonomy' => 'sp_events_cat' ) );
		wp_cache_flush();
	}