Downforce will be slashed by 10 percent next year, predominantly to help official tyre supplier Pirelli to cope.
Six-time world champion Lewis Hamilton has been highly critical of Pirelli's products in recent weeks, particularly after his problems at Silverstone.
"We constantly complain that we can't attack with these tyres," he told Speed Week.
Hamilton said he thinks the fundamental problem is that in the post-tyre war era, Pirelli lacks the pressure to improve.
"Now there's no incentive for them," the Mercedes driver said. "So it has to be us drivers who put the pressure on them."
Next year, ahead of the move to 18-inch wheels for 2022, Pirelli will supply fundamentally the same tyres as in the 2019 and 2020 seasons.
"If we had known (about the coronavirus crisis), they would have designed tyres that were a little more robust," said the FIA's Nikolas Tombazis.
To help Pirelli, downforce changes for 2021 will be introduced. On Carlos Sainz's car in Spa practice, McLaren simulated the floor change in front of the rear wheels.
Other aerodynamic changes to reduce aerodynamic load will also be introduced next year for the same reason.
"The three new measures should reduce downforce by 4-5 percent," Tombazis told Auto Motor und Sport.
"Together with the previously announced floor changes, we expect a total of 10 percent less downforce. But we also expect the teams to almost completely make up for that," he said.
