The production of Apple products has been halted in three major manufacturing plants across Shanghai due to the Chinese government’s current COVID-19 restrictions. Two of the production companies affected, Pegatron and Quanta, assemble iPhones and MacBooks for the tech giant and are unsure as to when they’ll be back up and running following this halt in production. Compal, a company that assembles the company’s iPads, will also be halting production temporarily.

Pegatron, the company that runs two Shanghai-based iPhone manufacturing plants, told Nikkei Asia that it hopes to “resume production soon,” however it wasn’t able to supply any concrete information on when that might be. Quanta’s MacBook production has similarly been on hold since the start of April, with no hopes of reopening in sight due to the latest wave of COVID-19 that’s been making its way throughout the world.

The manufacturing halt might have some major implications for the supply of Apple products in the next few months if all three production plants stay closed for an extended period of time. Supply shortages of technology have been rampant since the start of the ongoing pandemic, but an extended closure of three of Apple’s primary Chinese manufacturers could spell disaster.

Halting production at Pegatron’s two iPhone manufacturing plants could hit the market in a big way as the company is responsible for 20% to 30% of all iPhone production, Nikkei Asia estimates. Pegatron is in the midst of opening a manufacturing plant in India, but it isn’t running yet, so Apple could be in some hot water if COVID restrictions keep Pegatron out of the game for an extended period of time.

Quanta’s shutdown will likely impact the tech company’s supply of MacBooks as well,  but not just Apple. The manufacturer’s Shanghai location doesn’t just produce MacBooks, it also makes laptops for Dell and HP, so its production halt will be keenly felt.

As already mentioned, this isn’t the first time that tech production has been halted by COVID and likely won’t be the last. Companies like Samsung and Google have seen key launches derailed by shortages, and there’s seemingly no end in sight. Apple CEO Tim Cook’s mastery of the supply chain should come in handy here, with the company already weathering the worst of the storm in 2021. With a plethora of decentralized component manufacturers, it seems likely that the company can figure something out.