Norwegian Cruise Line plans to increase the automatic gratuities charged to guest accounts.

The new rates will take effect on April 1, 2018.

The line informed agents of the “nominal adjustment” to its daily service charges in an email today.

The new rates for standard cabins and mini-suites will go from $13.99 to $14.50 per passenger, per day. Charges for The Haven and other suite-level categories will go from $16.99 to $17.50 per person, per day.

On the all-inclusive Norwegian Sky and Norwegian Sun, the standard and mini suite charge will go from $18.99 to $19.99. And, the charge for suites will increase from $21.99 to $22.99.

Agents were notified that clients with bookings made by March 31 may prepay gratuities at the current rate. Payment must be made before the sail date. If clients have already prepaid gratuities, they won’t be affected by the changes.

The gratuity increase is in keeping with an industry trend. Both Royal Caribbean and Celebrity Cruises announced rate increases in January.