The United States Citizenship and Immigration Services on Friday announced that it was suspending the premium processing option for H-1B visas, which allowed companies to bring in highly skilled workers in a few weeks, rather than several months, if they paid an additional amount. A large number of technology companies, among other industries, relied on premium processing to bring in skilled engineers to the US.

Immigration services said the suspension applies to all H-1B petitions filed on or after April 3, 2017. It claimed it will last for at least six months, and that it would help them clear a backlog of applications. “We will notify the public before resuming premium processing for H-1B petitions,” the notice added.

Immigration lawyers told the Financial Times this would hit several companies very hard. The US caps the number of H-1B visas it gives out to 85,000 a year, and gets many more applications, leading to a lottery system. Nearly all major companies use the expedited process to apply for the visas on behalf of their employees. By delaying the processing, companies will be stuck with the uncertainty of whether a potential employee will be able to join or not, which some are already calling a “crippling” move.

Additionally, the premium processing fee of $1,225 for each application brings the US government millions of dollars in revenue every year, which it now stands to lose.

This comes even as the Donald Trump administration moves to tighten H-1B regulations as part of its conservative stance on immigration. This poses particular problems for India, which sends the maximum number of H-1B workers to the states. The Indian government has been attempting to lobby with the White House to reconsider tightening H-1B rules.