Not a single UN member state imported coal from North Korea in April, according to the 1718 Committee website which tracks and publishes shipments of the restricted commodity.

November’s UN Resolution 2321 added a cap on what was traditionally the North’s most lucrative export, limiting member states from importing more than 7.5 million tonnes or just over $400,000 worth of coal per year.

The measures also call for the 1718 Committee to monitor and publish data the shipments, which fell to zero in the fourth month of the year with no member states reporting any imports to the UN body.