SINGAPORE/PARIS (Reuters) – Boeing Co plans to release upgraded software for its 737 MAX in a week to 10 days, sources familiar with the matter said.

The U.S. planemaker has been working on a software upgrade for an anti-stall system and pilot displays on its fastest-selling jetliner in the wake of the deadly Lion Air crash in Indonesia in October.

Similarities between the flight path in the Lion Air incident and last week’s Ethiopian Airlines crash have raised fresh questions about the system, but so far there is no evidence on whether the same software is again a potential issue.

Asked about the timeline, first reported by AFP, a Boeing spokesman referred to a statement on Monday that the upgrade would be deployed across the 737 MAX fleet in the coming weeks.

The grounding of Boeing’s 737 MAX jets after the crash in Ethiopia has had no immediate financial impact on airlines using the planes, but it will get painful for the industry the longer they do not fly, companies and analysts said on Friday.

Regulators have grounded the 737 MAX around the world, and the U.S. planemaker has halted deliveries of the several thousand on order for a model intended to be the future industry workhorse.

Air Canada and United Airlines on Friday became the first major carriers in North America to warn of negative financial implications to business as a consequence of the grounding of the Boeing planes.

Air Canada suspended its 2019 financial forecasts, while United Airlines said it would see an adverse effect on its operations if the jets remained grounded heading into the peak summer travel season.