For every ace he serves this season, Andy Murray has pledged to donate £50 to help children who have fled their home countries.
The tennis star said that he was so moved by recent pictures of people desperate to reach Europe that he felt he had to do something.
For every ace from now until the end of the season, the world number three will give £50 to Unicef - a donation which will be matched by the Lawn Tennis Association, ATP and his sponsor Standard life.
He told the charity: “After I saw the recent images on the news, I felt I had to do something to help the millions of children and their families who have been forced to flee their homes.
“I’ll get that little bit more satisfaction from each ace I hit knowing that it will be helping Unicef keep children safe.”
He added: “I’m asking fans across the world to join with me to and support Unicef’s vital work. Together we can help make a safer world for every child.”
Murray’s promise could be an expensive one, given that he served 64 aces in just four matches in this month’s US Open, according to BBC Sport.
Unicef works alongside thousands of refugee children fleeing violence in war zones such as Syria. It also provides food, water, sanitation and medicine for young people still living in conflict zones.
Murray has been supporter of the charity since 2014.
He is set to play in the Davis Cup semi-final against Australia’s Thanasi Kokkinakis on Friday - where everyone will be hoping for plenty of aces.