Serena and Venus Williams will be reunited on court for the first time in four years after being handed a wild card into the doubles at the US Open, organisers confirmed on Saturday.
Serena Williams, who is expected to retire after the US Open, has not partnered elder sister Venus in a doubles event since the duo lost in the last 16 at the 2018 French Open.
They have not played doubles at the US Open since 2014.
Playing together, the Williams sisters were a dominant force in Grand Slam doubles tennis, winning 14 titles as well as three Olympic gold medals.
The last of their 14 Grand Slam doubles wins came at Wimbledon in 2016, 17 years after their first title together at the 1999 French Open.
Serena Williams, who turns 41 next month, is expected to confirm her retirement from tennis after the US Open, signing off from a career that has yielded 23 Grand Slam singles titles.
Venus Williams, 42, has not announced any plans to retire as yet.