Amazon is postponing the return of employees to its corporate offices by about four months, as the delta variant of the COVID-19 virus has led to an uptick of infections in the U.S. and elsewhere.

The ecommerce giant had been expecting most employees in the U.S. and other countries to come back to its office locations the week of Sept. 7, 2021. Under its revised plan, Amazon has set Jan. 3, 2022, as its official return-to-work date.

While many companies — including Google, Facebook, Netflix, Disney and Microsoft — are requiring workers returning office locations to be vaccinated, Amazon has not adopted that policy. However, Amazon will require employees coming back to the office to wear masks unless they show proof of full vaccination.

“As we continue to closely watch conditions related to COVID-19, we are adjusting our guidance for corporate employees in the U.S. and other countries where we had previously anticipated our employees would begin coming in regularly the week of Sept. 7,” Amazon head of HR Beth Galetti wrote in an email to employees, the Seattle Times reported. “We are now extending this date to Jan. 3, 2022.”

Meanwhile, workers at Amazon’s warehouse facilities and physical store locations have continued to work in-person throughout the pandemic. The company says it has provided millions of masks to all Amazon associates, delivery service partners, Amazon Flex participants, seasonal employees and Whole Foods Market stores employees and that the company has been “encouraging everyone to take and use them.” Amazon also says it has implemented social distancing at fulfillment centers, instituted temperature checks and taken other precautions like staggering shift start times and break times.

Amazon’s updated corporate office reopening plans were previously reported by GeekWire.