Pals Justin Bieber and Chris Brown were spotted heading into a studio together on Monday. According to Rap-Up.com, the singers met up at the Record Plant in Hollywood.

"Studio. #NEWMUSIC," Bieber tweeted early Tuesday morning, leading us to believe the session was for his next album.

Previously Bieber told MTV News that he wanted to focus less on features for his next album, but given the fact that Brown recently wrote a track for Joe Jonas, it's possible he may have just been assisting with some writing.

The rumored session marks the latest collaboration for the pair, who have appeared on two tracks together in the past. First, they remixed Bieber's slow jam "Up," then Bieber jumped on Brown's ballad "Next to You."

Bieber's producer, Danja, told Rap-Up.com that he's aiming for an "edgier" sound for the 17-year-old's next release. "What I'm creating for him I think is definitely a more mature sound. That's where he's headed now," he explained.

Earlier this year, Bieber's manager, Scooter Braun, revealed some other names the pop star hopes to get into the studio with, including Drake, a collaboration Bieber hinted at last year.

Bieber is also reportedly working with Kanye West. "Him and Kanye [West] had a call today about a song they're trying to work on together," Braun said. "Kanye wants to produce a bunch of songs for the new album."