Uber CEO Dara Khosrowshahi is standing by the company’s recent changes to employee benefits despite backlash from workers.

The ride-hailing company recently told workers they needed to return to the office to work in person three days a week and changed the eligibility for its month-long paid sabbatical benefit.

Starting in June, employees must work from the office three days a week—up from two—and eligibility for a month-long paid sabbatical was raised from five to eight years. Some previously approved remote workers were also asked to return to the office.

In an interview with CNBC following Uber’s Q1 earnings, Khosrowshahi said the company wanted people back in the office.

“We think it’s a great policy and it’s the right mix of giving your employees flexibility but also getting them to the office for those all-important teamwork tasks,” he said. “We want people in the office, we want them working hard.”

When pressed about workers who took the job with the remote work option, Khosrowshahi said they would have “to make a choice.”

“They’ve got to make their own choice, do they want to come to the office, or is working remotely really important for them? The good news is the economy is still really strong, the job market is strong,” he said. “People who work at Uber, they have lots of opportunities everywhere.”

“We want them, obviously, to take the opportunity with us, to take the opportunity to learn,” Khosrowshahi added. “But this is a company where you have to work hard, we’re not going to make excuses for that, and you have to work hard together.”