protected function update_post_meta( &$order ) {
		$updated_props     = array();
		$id                = $order->get_id();
		$meta_key_to_props = array(
			'_order_key'            => 'order_key',
			'_customer_user'        => 'customer_id',
			'_payment_method'       => 'payment_method',
			'_payment_method_title' => 'payment_method_title',
			'_transaction_id'       => 'transaction_id',
			'_customer_ip_address'  => 'customer_ip_address',
			'_customer_user_agent'  => 'customer_user_agent',
			'_created_via'          => 'created_via',
			'_date_completed'       => 'date_completed',
			'_date_paid'            => 'date_paid',
			'_cart_hash'            => 'cart_hash',
		);

		$props_to_update = $this->get_props_to_update( $order, $meta_key_to_props );

		foreach ( $props_to_update as $meta_key => $prop ) {
			$value = $order->{"get_$prop"}( 'edit' );
			$value = is_string( $value ) ? wp_slash( $value ) : $value;
			switch ( $prop ) {
				case 'date_paid':
				case 'date_completed':
					$value = ! is_null( $value ) ? $value->getTimestamp() : '';
					break;
			}

			$updated = $this->update_or_delete_post_meta( $order, $meta_key, $value );

			if ( $updated ) {
				$updated_props[] = $prop;
			}
		}

		$address_props = array(
			'billing'  => array(
				'_billing_first_name' => 'billing_first_name',
				'_billing_last_name'  => 'billing_last_name',
				'_billing_company'    => 'billing_company',
				'_billing_address_1'  => 'billing_address_1',
				'_billing_address_2'  => 'billing_address_2',
				'_billing_city'       => 'billing_city',
				'_billing_state'      => 'billing_state',
				'_billing_postcode'   => 'billing_postcode',
				'_billing_country'    => 'billing_country',
				'_billing_email'      => 'billing_email',
				'_billing_phone'      => 'billing_phone',
			),
			'shipping' => array(
				'_shipping_first_name' => 'shipping_first_name',
				'_shipping_last_name'  => 'shipping_last_name',
				'_shipping_company'    => 'shipping_company',
				'_shipping_address_1'  => 'shipping_address_1',
				'_shipping_address_2'  => 'shipping_address_2',
				'_shipping_city'       => 'shipping_city',
				'_shipping_state'      => 'shipping_state',
				'_shipping_postcode'   => 'shipping_postcode',
				'_shipping_country'    => 'shipping_country',
			),
		);

		foreach ( $address_props as $props_key => $props ) {
			$props_to_update = $this->get_props_to_update( $order, $props );
			foreach ( $props_to_update as $meta_key => $prop ) {
				$value   = $order->{"get_$prop"}( 'edit' );
				$value   = is_string( $value ) ? wp_slash( $value ) : $value;
				$updated = $this->update_or_delete_post_meta( $order, $meta_key, $value );

				if ( $updated ) {
					$updated_props[] = $prop;
					$updated_props[] = $props_key;
				}
			}
		}

		parent::update_post_meta( $order );

		// If address changed, store concatenated version to make searches faster.
		if ( in_array( 'billing', $updated_props, true ) || ! metadata_exists( 'post', $id, '_billing_address_index' ) ) {
			update_post_meta( $id, '_billing_address_index', implode( ' ', $order->get_address( 'billing' ) ) );
		}
		if ( in_array( 'shipping', $updated_props, true ) || ! metadata_exists( 'post', $id, '_shipping_address_index' ) ) {
			update_post_meta( $id, '_shipping_address_index', implode( ' ', $order->get_address( 'shipping' ) ) );
		}

		// Legacy date handling. @todo remove in 4.0.
		if ( in_array( 'date_paid', $updated_props, true ) ) {
			$value = $order->get_date_paid( 'edit' );
			// In 2.6.x date_paid was stored as _paid_date in local mysql format.
			update_post_meta( $id, '_paid_date', ! is_null( $value ) ? $value->date( 'Y-m-d H:i:s' ) : '' );
		}

		if ( in_array( 'date_completed', $updated_props, true ) ) {
			$value = $order->get_date_completed( 'edit' );
			// In 2.6.x date_completed was stored as _completed_date in local mysql format.
			update_post_meta( $id, '_completed_date', ! is_null( $value ) ? $value->date( 'Y-m-d H:i:s' ) : '' );
		}

		// If customer changed, update any downloadable permissions.
		if ( in_array( 'customer_id', $updated_props ) || in_array( 'billing_email', $updated_props ) ) {
			$data_store = WC_Data_Store::load( 'customer-download' );
			$data_store->update_user_by_order_id( $id, $order->get_customer_id(), $order->get_billing_email() );
		}

		// Mark user account as active.
		if ( in_array( 'customer_id', $updated_props, true ) ) {
			wc_update_user_last_active( $order->get_customer_id() );
		}

		do_action( 'woocommerce_order_object_updated_props', $order, $updated_props );
	}