Lewis Hamilton has agreed to undertake testing for Formula 1 tyre suppliers Pirelli this week at the Circuit Paul Ricard.
It's an unusual commitment from Hamilton, who is known to dislike taking part in testing sessions during the season. He's often pulled out of such tests in the past, citing injury or illness.
Hamilton feels there is little for him to gain personally by participating in such sessions. He jealously guards his downtime away from Grand Prix weekends. Usually, testing is left to his team mate or to one of Mercedes' test and development drivers.
In last month's all-team test at the Hungaroring, GP3 driver George Russell turned out for the team on both days. Valtteri Bottas was also in action, taking part in a one-day test for Pirelli.
Now it's Hamilton's turn to help the tyre manufacturer with its 2018 development programme. The test will be held on Thursday - and for once, he insists that he's keen to be there.
"I've got the test later this week which is very rare for me- I'm not a tester," the Briton admitted. "I'm looking forward to it. I offered to do it. So I'm looking forward to that - kind of."
Test opportunities are severely limited in Formula 1. However, Pirelli has been permitted 25 extra car days of in-season testing over the course of the year to help better prepare its tyre offering to teams.
Pirelli is understandably keen to get the input of the current championship leader on their latest compounds. But quite why Hamilton is also so eager to get behind the wheel for a test session is less clear.
It could be related to the venue for the test. The Circuit Paul Ricard will host next year's French Grand Prix, after a ten year absence for the event from the line-up of Formula 1 events.
The 5.861km (3.642-mile) circuit was formerly owned by former Formula 1 supremo Bernie Ecclestone. The circuit management has been carrying out modifications to the track ahead of its return to the calendar. A new chicane is to be added half-way down the long Mistral straight.
"The speed before the chicane will be 343km/h," managing director Gilles Dufeigneux explained. "The chicane has been added to prevent the engines from running at full speed."
The changes will also allow for a new overtaking area on the circuit. The new layout was presented to drivers including Hamilton, Sebastian Vettel and Fernando Alonso at the Austrian Grand Prix in July.
By agreeing to undertake testing this week, Hamilton will have an early opportunity to get a feel for the circuit.
Paul Ricard hosted the French Grand Prix on 14 occasions between 1971 and 1990. Two different configurations - the Long Circuit and the Club Circuit - were used during this period. The last winner at Paul Ricard was Alain Prost, driving for Ferrari.
The circuit's use was subsequently limited to motorcycle racing and French national racing. After it was purchased by Bernie Ecclestone in 1999 it was converted into an advanced test track.
The circuit is able to deliver wet weather conditions for testing, with a two-day F1 wet test taking place at the end of May. Robert Kubica has also taken part in testing at Paul Ricard in July, completing 90 laps in a 2012-spec Lotus E20.
Last season, only Mercedes, Red Bull and Ferrari had the resources to prepare the 'mule' car required for Pirelli test days. This year every team has agreed to run at least one test day to work on 2018 specifications.