The present invention relates to a formulation comprising a polyether siloxane, which is characterized in that a polyether that is terminated with an ester group and that is different from the polyether siloxane is present in the formulation in an amount of from 0.5 to 10% by weight based on the complete formulation, to a process for the production of a defoamed composition, wherein the inventive formulation is added to the composition to be defoamed, and to a composition comprising a formulation according to the invention, wherein the composition is a coating agent, a paint or a varnish.