Finneas has teased progress on his sister Billie Eilish's upcoming album.
The Let's Fall in Love for the Night artist produced and co-wrote his sister's first two albums, When We All Fall Asleep, Where Do We Go? and Happier Than Ever.
Now, he has given an update on Billie's next full-length effort, revealing it is "85 per cent done".
However, while speaking to Mr Porter, the producer admitted the process hasn't been easy.
"I don't think Billie was particularly sure about how she actually felt about the things we were trying to write about. Making a thing that you feel really connected to - it can really evade you," he shared.
Finneas also noticed that his songwriting skills had "got a little rusty" due to his full-on touring schedule.
"And that was scary," he added. "It was discouraging to realise that if I take time off, my songwriting muscle atrophies. I had to get back in shape."
The 26-year-old told the outlet that he planned on managing his music-making schedule better in 2024.
"I love to create," he said. "But I don't love drowning in it. So, I'm trying to have a more regulated relationship with it. I'm producing responsibly."
In a recent appearance on The Tonight Show Starring Jimmy Fallon, Billie teased that her next album was "almost done" but neglected to give a release date.
"At some point, you will know more," she said on the show, "but I'm not going to say anything."
Billie's song What Was I Made For?, which appeared in 2023's Barbie movie, is currently nominated for five Grammys and a Golden Globe.