Uranium miners extended a rally that’s made them the best-performing Australian stocks this year after the world’s biggest producer of the metal used to produce nuclear fuel cut its output target.

Kazatomprom lowered its guidance for production for this year by 12% to 14%. The company, listed in London and controlled by the Kazakhstan government, had warned in January that it was likely to fall short of its output goals over the next two years.

Paladin Energy Ltd. shares jumped as much as 7.4% in Sydney and Boss Energy was up as much as 8.1%. A couple of smaller miners surged even more: Deep Yellow, which has projects in Australia and Namibia, soared more than 18%, while Bannerman Energy climbed as much as 8.3%.

The production warning is the latest in a series of supply setbacks — including a coup in Niger last year that disrupted shipments to Europe — that have pushed spot uranium prices to 15-year highs. That’s happening amid a revival of interest in nuclear power as governments try to decarbonise their economies to meet net zero targets.

The reduction in output from Kazakhstan “just leaves the market in even more of a deficit than it already is,” said Matt Griffin, co-portfolio manager of Australian small companies at Maple Brown Abbott. There’s unlikely to be any impact on Australian production, but “prices are going to be higher across the board,” he said.

Boss Energy and Paladin, both based in Perth, are the two best-performing stocks on Australia’s benchmark S&P/ASX 200 Index this year, rising 48% and 39%, respectively.

Uranium miners in other parts of the world also rose following the Kazatomprom announcement. CGN Mining advanced as much as 8.2% in Hong Kong, while Cameco closed up 5.9% in New York on Thursday. The Global X Uranium ETF, which tracks the performance of several miners, jumped 6.2% on Thursday to the highest level since 2014.