Organopolysiloxane compositions obtainable by reaction of (a) essentially linear organopolysiloxanes which are terminated at both ends by Si-bonded hydroxy groups, (b) optionally, plasticizers, (c) at least one dialkylaminomethylalkyldialkoxysilane chain extender and/or partial hydrolysate thereof, (d) at least one deactivator, (e) optionally, one or more alkyltrialkoxysilanes and/or partial hydrolysates thereof, and (f) optionally, catalysts for accelerating the reaction of silane (e) with Si—OH groups, are useful in low-modulus compositions which can be crosslinked at room temperature, in particular, compositions which crosslink with elimination of alcohols.