A method for controlling the thickening of aqueous systems comprising silicates, which comprises adding to the aqueous system at least one copolymer of a mean molecular weight Mw of greater than 60 000 g/mol and the copolymer being made up essentially randomly from monoethylenically unsaturated monocarboxylic acids, monoethylenically unsaturated dicarboxylic acids and optionally other ethylenically unsaturated comonomers, the quantitative figures being respectively based on the total amount of all monomers used.