We pass the question whether par. 20 of the defendant’s answer was sufficient to raise the affirmative defence of novation (see Mass. R.Civ.P. 8[c], 365 Mass. 750 [1974]) because the undisputed facts set out in pars. 7,11 and 15 through 17 of the defendant’s answers to interrogatories and in his affidavit in opposition to the motion for sum*948mary judgment are insufficient as matter of law to warrant a finding that the plaintiff discharged the defendant from any existing liability to it. See Traveler Shoe Co. v. Koch, 216 Mass. 412, 415 (1914); Kirtley v. C.G. Galbo Co., 244 Mass. 179, 182-183 (1923); Larson v. Jeffrey-Nichols Motor Co., 279 Mass. 362, 365-366 (1932); Tudor Press, Inc. v. University Distrib. Co., 292 Mass. 339, 341 (1935); Harvard Elec. & Mach. Co. v. G & K Provision Co., 333 Mass. 678, 682-683 (1956).

Judgment affirmed.