MotoGP teams will keep the same bikes for the start of the 2021 season as part of cost-cutting measures to limit the financial impact caused by the coronavirus pandemic.
Motorcycling officials announced on Thursday that no development work will be allowed this season on bikes which were homologated at the start of the year.
"These changes are designed to reduce the costs incurred by the ongoing Covid-19 crisis whilst maintaining fairness and equality in order to conserve the entertainment value of the sport and the integrity of the competition," the International Motorcycling Federation (FIM) said in a statement.
"There will be no update of any homologated parts during the 2020 season. This applies to all manufacturers."
It added: "Manufacturers must start the 2021 season using March 2020 homologated parts. Thereafter, normal upgrade regulations will apply for the rest of the 2021 season as per current regulations."
That means non-concession teams Honda, Yamaha, Ducati and Suzuki will be unable to develop their engines during the 2021 campaign. Riders will also be limited to just two bikes per season.
A freeze on development will apply until the end of the 2021 season in both Moto2 and Moto3.
The first eight races of the 2020 season have been cancelled or postponed. The German MotoGP at the Sachsenring on 21 June, the next scheduled event, is also in doubt following an extension to the ban on large-scale public events in the country.