A Japanese airline has launched a new initiative to help reduce carbon emissions: Have passengers use the bathroom before boarding.

All Nippon Airways said empty bladders means lighter passengers, which means less fuel needed to transport them, the Daily Mail reported.

The airline reportedly has placed staff at boarding gates to ask passengers to relieve themselves before getting on their flights.

All Nippon hopes the one-month trial, which started Oct. 1, will reduce carbon emissions by five tons in 30 days, the Daily Mail reported.

If it is effective and well-received, the airline may extend the initiative, the paper reported.

Click here for more on this story from the Daily Mail.