Blizzard has an expansion planned for Diablo III, the company has announced.

During an earnings call for the third quarter of its current fiscal year, Blizzard CEO Mike Morhaime said that although an expansion is currently planned, no timeline is in place just yet for when it might be released.

“We do have an expansion planned for Diablo, [but] I don’t have any timeline to talk about. I think the most important thing for us always comes down to the quality of the expansion and the gameplay, so that will be a big factor in terms of driving our schedule,” he said.

Diablo III has sold over 10 million copies as of the September 30, making it the top-selling PC game in terms of both dollars and units in North America and Europe.