After the social media company confirmed on Tuesday that Tesla CEO Elon Musk had joined its board of directors, former Tesla board member Steve Westly warned Twitter that it would have to learn to work at Elon Musk’s pace.

“My advice to Twitter executives is put on your track shoes now because Elon is going to push you to pick up the pace,” Westly told Bloomberg on Tuesday. “Here we are day one into this and he’s already saying ‘Hey, maybe it’s time to get that edit function in there.’ I think he’s going to shake things up,” the Tesla investor added.

Tesla’s CEO is also known for his intensity. He has pushed for lofty goals at Tesla and SpaceX, and has been known to work up to 120 hours a week and sleep on the production floor. Former executives have stated the billionaire can be challenging to work for, prone to bouts of rage and even instances of rage-firing workers — claims he has categorically refuted, branding them “false” on Twitter and saying he provides “clear and frank” feedback to colleagues.

Before the appointment that Musk had joined Twitter’s board, the billionaire tweeted a poll: “Do you want an edit button?” A day later, Twitt