Order unanimously affirmed without costs. Memorandum: In this contract action, plaintiffs contend that they are entitled to summary judgment because defendant's only opposition to their motion was based on the unpleaded defense that decedent had released him from the debt arising from the contract. Defendant's assertion of this unpleaded defense neither surprised nor prejudiced plaintiffs, and therefore it was properly considered by Supreme Court (see, Olean Urban Renewal Agency v Herman, 101 A.D.2d 712, 713). Because factual questions exist whether this purported release or covenant not to sue was signed by decedent, or whether decedent intended the debt arising from the contract to be embraced within the fair import of its terms (see, Farnham v Farnham, 204 App. Div. 573), plaintiffs' motion and defendant's cross motion for summary judgment were properly denied (see generally, Starr v Johnsen, 143 A.D.2d 130, 132; TLC Med. Transp. Servs. v Syracuse City School Dist., 133 A.D.2d 529).