Europe is finding a steady flow of liquefied natural gas (LNG) carriers coming from an unlikely source. The Wall Street Journal reports that, while Russian pipeline gas has dwindled down to a trickle, the continent’s importers are quietly splurging on frozen Russian gas, in the form of LNG, delivered by sea. 

European Union imports of Russian LNG jumped by 41% in the year through August, making Russia Europe’s second-largest source of LNG, after the U.S. 

Read more: Europe’s Natural-Gas Crunch Sparks Global Battle for Tankers

Importers argue the shipments aren’t covered by EU sanctions and that buying LNG from Russia alongside other suppliers helps keep European energy prices in check. Yet the trade runs counter to the EU’s efforts to deprive Russia of fossil-fuel revenues. 

The EU will sharply restrict imports of Russian crude oil in December but has spared gas imports. The ship transport has also made Russia the world’s fourth-biggest LNG exporter after Australia, Qatar and the U.S.