Use of copolymers containing sulfonic acid groups which comprise (a) 30 to 95 mol % of at least one monoethylenically unsaturated carboxylic acid, one monoethylenically unsaturated carboxylic ester or one water-soluble salt of a monoethylenically unsaturated carboxylic acid, (b) 3 to 35 mol % of at least one monomer containing sulfonic acid groups of the formula I in which the variables have the following meanings: R is hydrogen or methyl; X is a chemical bond or —COO—R1—; R1 is unbranched or branched C1-C4-alkylene; M is hydrogen, alkali metal or ammonium, and (c) 2 to 35 mol % of at least one nonionic monomer of the formula II in which the variables have the following meanings: R2 is hydrogen or methyl; R3 is a chemical bond or unbranched or branched C1-C6-alkylene; R4 are identical or different unbranched or branched C2-C4-alkylene radicals; R5 is unbranched or branched C1-C6-alkyl, C5-C8-cycloalkyl or aryl; n is 3 to 50, in random or block copolymerized form, as additive for detergents and cleaners.