The government has agreed to accept a Labour demand to require the Civil Aviation Authority to have a greater duty to take account of the environmental effects of the airports it regulates.
Labour put forward the suggestion on 17 November 2012 during report stage of the Civil Aviation Bill, which deals with the regulation of the UK's major airports.
The government had put down amendments requiring the CAA to look at the "desirability" of holders of airport licences taking "reasonable" measures to reduce the adverse environmental impact of their airports.
But Lord Davies of Oldham said that while this would be an "improvement" on the bill it was "not significant enough".
"This is an area of crucial aviation policy with regard to airports and we are saying...that in place of what is in fact a fairly wishy-washy concept of desiring things to happen that there should in fact be an obligation," he said.
Initially, Transport spokesman Earl Attlee maintained that the government's amendments were sufficient, and Labour's were unnecessary.
But Lord Davies countered that Labour was merely "pressing the government to show the proper concern for the environment", arguing that the word "desirability" was not an "expression of a will to get things done".
Earl Attlee said his opposite number was "very insistent and persuasive" and agreed to accept the amendments, adding that his bill team manager would probably "kill" him.