Twitter has asked a number of people it fired this week to return to the company, because it actually still needs their skills to build the features Elon Musk wants, Bloomberg reports. The flailing social network let go of about half of its roughly 7,000 on Friday, but that was before management realized just how vital some of those people were to the company’s functions. Some, according to Bloomberg, were even let go by mistake. Musk had defended the decision to fire half of the company, arguing (in a tweet) it was a necessary move “when the company is losing over $4M/day.” He also claimed each employee who was fired would receive three months severance, though it is unclear if an employee would have to return that money if they are asked to return.