Rooney Mara and Joaquin Phoenix’s growing family will also honor their past.

The happy couple have welcomed their first child together, naming the baby boy River after Phoenix’s late brother, who died in 1993.

Russian filmmaker Victor Kossakovsky made the joyous announcement Sunday at the 2020 Zurich Film Festival, where he was presenting his and Phoenix’s documentary “Gunda.”

“A beautiful son called River,” Kossakovsky said.

River Phoenix, the bright star of “Stand By Me,” “Running On Empty” and “My Own Private Idaho,” died of an accidental drug overdose in West Hollywood when he was just 23. His younger brother Joaquin, 19 at the time, was at the club where the incident occurred and placed the 911 call.

“River was a really substantial actor and movie star, and we didn’t really know it,” Joaquin Phoenix told “60 Minutes” earlier this month in a rare interview about his brother. “And so during that time in which you’re most vulnerable, there are helicopters flying over. There are people that are trying to sneak onto your land. Certainly, for me, it felt like it impeded on the mourning process, right?”

Phoenix, 45, and Mara, 35, met on the set of the 2013 movie “Her” and made their red carpet debut together at the 2017 Cannes Film Festival, where he won the best actor award for “You Were Never Really Here.”

The two confirmed their engagement last year after Mara was spotted wearing a large diamond ring.