Abstract: In a polydiorganosilixane composition which is capable of storage in the absence of moisture and can be cured at ambient temperature under the action of water or moisture to give elastomers, the composition comprising a diorganosiloxane having reactive terminal groups, a diorganosilane having groups which are sensitive to hydrolysis, a cross-linking agent, and optionally fillers which have a thixotropic effect, condensation catalysts and/or other known auxiliaries, the improvement which comprises employing as the silane (a) a silane of the formulaRR.sup.1 Si(NR.sup.2 R.sup.3).sub.2plus (b) an organosilane of the formulaRSi (O--N.dbd.R.sup.4).sub.3in whichR, R.sup.1, R.sup.2 and R.sup.3 each independently is alkyl, aryl, aralkyl and vinyl groups, orR.sup.2 and R.sup.3 together can be an alkanediyl radical having up to 8 C atoms or hydrogen, andR.sup.4 is an R.sup.2 R.sup.3 C group having up to 8 C atoms.