Seven & I Holdings and other retailers in Japan are warning customers of possible Asahi Super Dry beer shortages after a cyberattack paralyzed production and distribution at Asahi Group Holdings.

Shoppers at some 7-Eleven stores are seeing notices that shipments of the country’s most popular beer had been suspended, as well as for Mitsuya Cider soda and private brand products such as Seven Premium Clear Cooler. Inventory varies from store to store, making it hard to say how imminent any shortages might be, a Seven & I representative said.

The disruption underscores how Japan’s food and beverage sector depends on intricate logistical and digital supply chains, where a single cyberattack can ripple from factory floors to convenience store shelves. Asahi’s troubles carry outsized weight given Super Dry’s dominant market share and the cut-throat competition among Japan’s major brewers.

Asahi halted production at some of its factories on Monday after a cyberattack hobbled its ordering and delivery system. As of Thursday evening, Asahi had no timeline for when it would be able to get its systems back online.

That’s weighing on the beverage maker’s shares, which are down 12% over the past week. Asahi competes with Kirin Holdings and Suntory Beverage & Food a cutthroat and saturated Japanese market.

Restaurant operator Kisoji has reached out to liquor stores to get extra stock of Asahi beer and is considering switching to Suntory or Kirin brands, a spokesperson said. Restaurant operators including Zensho Holdings said that it does not expect inventory to run out "anytime soon.”