President Trump’s executive order on Monday temporarily suspending many new work visas until the end of 2020 and preventing hundreds of thousands of foreign workers from seeking U.S. jobs was met with consternation by many business leaders, particularly in the tech industry.

Tesla and SpaceX founder and CEO Elon Musk, originally from South Africa and someone Trump has openly admired, took to Twitter on Monday night to lament the administration’s move, saying, “Very much disagree with this action. In my experience, these skillsets are net job creators. Visa reform makes sense, but this is too broad.”

The order takes aim at a number of work permits, including the H-1B visa, which allows skilled workers such as computer programmers to work in the U.S. for a renewable three-year stint that can serve as a springboard to permanent residency.

In a statement, Trump said that the ban stems from the government’s “moral duty to create an immigration system that protects the lives and jobs of our citizens.” But tech luminaries, many of whom are immigrants or children of immigrants themselves, disagreed, arguing that foreign workers are key to American prosperity.

Microsoft president Brad Smith tweeted, “Now is not the time to cut our nation off from the world’s talent or create uncertainty and anxiety. Immigrants play a vital role at our company and support our country’s critical infrastructure. They are contributing to this country at a time when we need them most.”

This is not the first time Microsoft—whose CEO, Satya Nadella, is an immigrant from India—has dealt with limits in bringing in qualified workers to the U.S. In 2007, the company opened a massive new facility in Vancouver, two hours north of its headquarters near Seattle, to take advantage of Canada’s more favorable immigration laws for skilled workers.

On Tuesday morning, Shopify CEO Tobi Lütke, a German immigrant to Canada, tweeted out an invitation to tech workers wanting to immigrate to the U.S. to think about Canada instead, where the e-commerce powerhouse is based.

Some CEOs spoke in personal terms. Susan Wojcicki, chief of Alphabet’s YouTube division, said on Twitter: “Immigration is central to America’s story, and it’s central to my own family’s story. My family escaped danger and found a new home in America…At YouTube, we join Google in standing with immigrants and working to expand opportunity for all.”

Other large companies to lament the order include Amazon, Twitter, Google, and Box.

Amazon argued that the order hurts the U.S. at a time when there is global competition for talent and many jobs are going unfilled. “Preventing high-skilled professionals from entering the country and contributing to America’s economic recovery puts America’s global competitiveness at risk,” Amazon tweeted from its Amazon Public Policy account.

The broader business community also expressed its reservations. “Putting up a ‘not welcome’ sign for engineers, executives, IT experts, doctors, nurses, and other workers won’t help our country, it will hold us back,” said U.S. Chamber of Commerce CEO Thomas Donohue.

The order, which also targets seasonal workers in the hospitality industry, students on work/study summer programs, and au pairs, could affect hundreds of thousands of people. It would also hinder multinational companies from transferring employees to the U.S. even for temporary assignments.

This is also not the first immigration issue on which the Trump administration and Big Business have disagreed recently. Last week, when the Supreme Court ruled against the Trump administration’s challenge to the DACA program, which allowed noncitizens brought to this country illegally as children to apply for protection from deportation, Walmart praised the decision, saying such people “are an important part of our team and help make us a better, stronger company.”