A Process for the preparation of materials crosslinkable with elimination of alcohols to give elastomers, wherein (A) an organopolysiloxane having at least two hydroxyl groups, (B) trialkoxysilanes and/or the partial hydrolysis products thereof in an amount of at least 0.7 part by weight, based on 100 parts by weight of component (A), (C) an organosilicon compound which comprises at least one radical bonded to silicon via carbon and having basic nitrogen, (D) a tin catalyst, optionally, (E) fillers, (F) stabilizers and (G) further substances are mixed with one another, (A) and (B) forming a reaction product with elimination of alkanol, with the proviso that tin catalyst (D) is added to the component (A) or the mixture containing the reaction product thereof only when from 1 to 60% of the Si--OH groups originally present remain present.