Previously, many immigrants were able to extend their work permits automatically upon submission of a renewal application. Now, U.S. Citizenship and Immigration Services is doing away with that policy, and forcing people to wait until a renewal request is approved before any extension.

That change, which went into effect Thursday, is significant because it can take the federal government months to process renewals due to a massive backlog of applications. That means immigrants could lose their jobs if their work permit expires before their renewal process is completed by USCIS.

As WGBH reports, immigrants are able to begin applying for renewal six months before the expiration of their work permit, though approvals can often take longer than that.

Ultimately, experts believe this policy could lead to immigrants being let go by their companies because they don’t have a work authorization. Additionally, it could enable companies to exploit immigrants by continuing to use their labor off the books.

“The change will have devastating effects on businesses who will lose valuable employees and on workers who will lose their authorization to support themselves and their families,” Lucas Guttentag, a Stanford law professor, told HuffPost.

Groups that could be affected by this policy include asylees, refugees and spouses of certain visa holders. People who have already received a work permit extension prior to Oct. 30 will not be affected.

The Department of Homeland Security has claimed this policy change is intended to prioritize “the proper screening and vetting of aliens before extending the validity of their employment authorizations,” but people whose work permits are up for renewal have already been screened to obtain those permits in the first place.

“These are workers that have the legal right to work in this country … they’ve been vetted, they’ve gone through the background checks,” says Victor Narro, the project director for the UCLA Labor Center.

A USCIS spokesperson did not immediately respond to a request for comment.

Immigration experts see the regulatory change as another prong of the Trump administration’s efforts to make the climate in the U.S. more hostile for immigrants.

“This is another tool in the process of the Trump administration’s effort to get people to self-deport,” Narro told HuffPost.