For the past 84 years, an exemption in U.S. law allowed the import of goods produced by slaves and others forced into labor, including children, as long as demand exceeded supply. In two weeks, that will be illegal.
President Barack Obama signed a trade bill Wednesday that includes a provision closing a loophole in a law that went into effect in 1932.
That measure, the Tariff Act of 1930, did prohibit slave labor imports, but said the ban did not apply to any goods that were not otherwise produced in large enough quantities to "meet the consumptive demands of the United States."
WATCH: Obama Signs Trade Bill Closing Loophole
The new bill was introduced last year as rights groups called attention to abusive labor practices, particularly in the fishing industry in southeast Asia.
The U.N.'s International Labor Organization estimates 21 million people are victims of forced labor worldwide, more than half of them in the Asia-Pacific region. That labor brings companies more than $150 billion in illegal profits, according to the U.N. Merchandise ranges from electronics to seafood to other agricultural goods.
Human Rights Watch, which reported last year on people from Cambodia and Myanmar being forced to work on Thai fishing boats, has called closing the U.S. import loophole a "no-brainer."
The new law goes into effect in 15 days. It calls for Congress to receive a yearly report with the number of times merchandise was denied entry because of the forced labor prohibitions, as well as a description of what kind of goods were rejected.
FILE - Burmese workers Tin Nyo Win, left, and Mi San smile upon being reunited in Samut Sakhon, Thailand, Nov. 9, 2015. They were separated while trying to escape the shrimp shed where they were held as slaves.