For 85 years, the U.S. government has turned a blind eye to companies that import goods derived from slavery -- so long as domestic production couldn’t meet demand for those goods. That’s about to change.

The U.S. Senate on Thursday voted to close a loophole in the Tariff Act of 1930, which bars goods made by convict, forced or indentured labor, amid a new focus on slavery in the supply chains of global companies. Almost 21 million people are enslaved for profit worldwide, the United Nations says, annually providing $150 billion in illicit revenue.

The legal gap has been in place for so long that politicians who pushed for the change aren’t exactly sure how it will affect businesses cited by human rights groups or the agencies responsible for blocking goods derived from slavery.

“The old system that leaves the door open to child or slave labor if it’s used to make a product that isn’t made here in the U.S. -- that system absolutely must end, and it will,” U.S. Senator Ron Wyden, an Oregon Democrat who spoke against the loophole on the Senate floor, said Thursday in a statement.

The Senate vote was part of a wide-ranging trade enforcement bill approved 75 to 20, its passage led by Republicans. The House of Representatives passed the bill last year. A statement from the White House on Thursday said President Barack Obama intended to sign the bipartisan legislation. It didn’t mention the language to close the loophole, one of many amendments to the bill.

Game Changer

The act may be a game changer for U.S. Customs and Border Protection and U.S. Immigration and Customs Enforcement, the agencies responsible for preventing goods derived from slavery from entering the country. Kenneth Kennedy, a senior policy adviser for ICE, has called the loophole “the Achilles heel” of the Tariff Act. To illustrate his point, he has used well- documented problems with the cocoa industry that supplies candy companies.

“If we know cocoa is being produced on plantations in West Africa using slave labor, and then being imported into the U.S., we still have to allow it in because the U.S. cannot produce enough cocoa to meet U.S. demand,” Kennedy said in a December interview.

Wyden’s spokesman, Keith Chu, said the senator hopes the closure of the loophole will allow enforcement agencies to crack down on slave labor, though he didn’t say which industries or companies might be targeted. Wyden and Senator Sherrod Brown, a fellow Democrat from Ohio, offered the amendment behind the loophole’s closure.

“Ending this provision gives those fighting forced labor the confidence they can challenge imports of these products without fear of being undermined by an archaic and outrageous provision of U.S. trade law,” Chu said in an e-mail.