Boeing had been working on the software upgrade since Lion Air’s crash in October 2018.

Following a statement from the U.S. Federal Aviation Administration that it would mandate “design changes” in Boeing’s 737 MAX 8 aircraft, the airplane maker confirmed that it would do so by April.

On Sunday, Ethiopian Airlines crash in connection to a software upgrade. Boeing’s statement expressed its deep condolences to the relatives of the 157 people who died in the crash.

Its statement also mentioned that in the aftermath of the October crash of Lion Air’s aircraft, it has “been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer.”

The software upgrade “will be deployed across the 737 MAX fleet in the coming weeks,” said Boeing.