A federal judge in Boston has blocked the Trump administration from imposing fines of up to 1.8 million dollars on migrants who fail to leave the US after final deportation orders. US District Judge George O’Toole ruled on Monday that the fines were imposed unlawfully.

The ruling came in a class-action lawsuit filed by migrants who were assessed civil penalties by the Department of Homeland Security. The judge said collecting the fines would likely drive the plaintiffs into insolvency, calling the amounts exorbitant.

The administration had been levying fines of 998 dollars per day on migrants who stayed after a deportation order. The fines were applied retroactively for up to five years, reaching a maximum of 1.8 million dollars per person.

The department said it had issued more than 103,000 fines totalling about 84 billion dollars since Trump returned to office. Congress authorized such penalties in 1996, but no administration used them until Trump’s first term.

The Department of Homeland Security had no immediate comment. The ruling is the latest court setback for the administration’s immigration crackdown.