Amazon is ending its contract with embattled security contractor Security Industry Specialists (SIS) in favor of two union-backed firms.

SIS announced that it would shed more than 1,000 employees in Seattle, according to a notice filed Wednesday with the Washington Employment Security Department. The majority of SIS’ full-time employees are expected to be rehired under the new contract.

“Our onsite security needs have changed over the years and we have selected two vendors that can scale with us,” an Amazon spokesperson in a statement shared with GeekWire. “All employees of the current security vendor will have the opportunity to apply to the new vendors.”

Local labor union SEIU6 said that security contractors Allied Universal and Securitas had won the bidding contract and that Allied would employ security workers in the company’s Seattle headquarters.

“It’s a huge win,” said Greg Ramirez, director of organizing at SEIU6. “We’re hoping it’s a step in the right direction for Amazon.” The labor organization currently represents around 600 union janitors at Amazon.

Amazon started working with SIS in 2012 after cutting ties with its former security contractor, Andrews International. Unlike Andrews, SIS workers are not backed by a union. Los Angeles, Calif.-based SIS is active in more than 200 cities and has nearly 600 clients.

Labor organizers protested Amazon’s use of SIS’ non-union labor earlier this month during the annual May Day march and outside of the company’s annual shareholders meeting. Rev. Jesse Jackson has been among those calling for Amazon to adopt a union contractor. SIS has also come under fire for allegedly mistreating its Muslim workers.

Ramirez said that the workers, who received the news on Friday, would be transitioned between now and the end of July when the layoffs are set to take effect.

Amazon uses security workers for its sprawling headquarters in Seattle that has grown to nearly 40 buildings near downtown where more than 45,000 employees work for the tech giant.

The annual May Day March in Seattle makes its way past Amazon HQ. The Bezos art is from a local union group advocating for Amazon security workers. #MayDaySEA pic.twitter.com/gZbTtVQy9A — GeekWire (@geekwire) May 1, 2019

Google ended a contract that it had with SIS in 2014 following complaints that the security company paid low wages and treated its workers unfairly. The tech giant opted to use in-house security instead of finding another contractor.

This story has been updated with information from Amazon and SEIU6.