Late last week, the Facebook and Instagram parent company laid out the precise details of its return-to-office mandate in a staff memo, the details of which were published by Insider.

Describing the shift as an “In-Person Time Policy,” Meta’s head of HR Lori Goler reiterated that from Sept. 5, it would be mandatory for all employees—except those with management-approved exemptions—to be back in the office three days a week.

Meta first told its employees in June that it was updating its remote work policy, meaning they would be expected to work from their assigned offices at least three days a week from September—a move that came much later than many of its Big Tech peers like Google, Apple, and Twitter.

The social media titan said at the time that this “distributed work” framework would allow its staff to “make a meaningful impact both from the office and at home.”

It marked a significant U-turn from CEO Zuckerberg’s pandemic-era assertions that half of Meta’s tens of thousands of employees could be working remotely by the end of the decade, and that the tech giant would become “the most forward-leaning company on remote work.”

Meta clamping down on RTO

According to Thursday’s note to Meta staffers, employees who don’t comply with the new rules could face “termination,” or see their failure to show up at the office impact their performance reviews.

Those who are exempted from the three-days-a-week RTO rule reportedly include employees who were hired in fully remote positions, or those already approved to continue working from home full-time.

According to Insider, no one who has worked for the firm for less than 18 months will be permitted to work fully remotely, and those who have worked at Meta for at least a year and a half will need to formally apply and be granted approval if they wish to work from home every day.

On the flip side of the new rules, employees who are permitted to remain fully remote will have caps introduced on how often they can work from Meta’s offices.

According to the report, those approved for remote work are being banned from coming into the office more than four days every two months unless there is a “clear business reason”—like an on-site event or a compulsory meeting—that indicates they should be on-site.

Management will track employees’ office attendance using data from their ID cards—which are used to gain entrance into Meta offices—as well as internal tools that workers use to display where they’re working from, according to the note.

Under the new rules, employees will be required to update their location status daily, Insider reported.  

A Meta spokesperson told Fortune via email on Monday that Meta believed “distributed work” would continue to be important to its success in the future.

“In the near-term, our in-person focus is designed to support a strong, valuable experience for our people who have chosen to work from the office, and we’re being thoughtful and intentional about where we invest in remote work,” they said.

The company’s spokesperson did not elaborate on why remote-approved workers were barred from going into the office more than four days every two months.

Back in March, Zuckerberg hinted that the tech giant would soon begin rolling back its remote work allowances, telling employees management was “committed to continuously refining our model” when it came to remote and hybrid work and touting the benefits of working in the office.

“We’re focusing on…finding ways to make sure people build the necessary connections to work effectively,” he said at the time. “In the meantime, I encourage all of you to find more opportunities to work with your colleagues in person.”