President Donald Trump signed an executive order ending the “de minimis” trade exemption from tariffs—a loophole that allowed companies like Temu and Shein to ship goods to the United States without paying import duties so long as they were valued at or under $800.

The low-cost shipments were previously excluded from tariffs; President Trump said the loophole has allowed countries to avoid taxes and smuggle drugs into the U.S.

In a flurry of trade news on Wednesday, Trump imposed new rates on copper imports and ended the de minimis exemption.