*811OPINION
By the Court,
Thompson, J.:This is an appeal from a summary judgment granted to Transnational Insurance Company in an action for declaratory relief filed against A. E. Ferrand, Steven Ferrand, William Fer-rand and Robert Vigoren. Only Vigoren appeared to defend.1 The purpose of the action was to secure an adjudication that Transnational’s automobile insurance policy issued to Richard Doherty for his Chrysler automobile does not cover accidental injuries sustained by Robert Vigoren while a passenger in that car. That policy insured Doherty, and any other person using the automobile with his express or implied permission against loss for liability imposed by law for damages arising out of the ownership, maintenance or use thereof. It was Transnational’s contention that Doherty was not the owner of the car when he purchased the insurance policy since he had sold it to A. E. Ferrand upon conditional sale and Ferrand thereafter enjoyed the exclusive possession and control of the vehicle. Subordinately, Transnational contended that when the accident occurred the driver of the car, Steven Ferrand, son of A. E. *812Ferrand, was not driving with the express or implied permission of Doherty and that Doherty’s policy of insurance therefore was not available to Robert Vigoren, the injured passenger. The district court agreed with Transnational and entered summary judgment in its favor. This appeal by Vigoren followed.
All relevant facts, except one, are undisputed. Robert Vigoren, a passenger in the back seat of the Chrysler automobile, was blinded by the accidental discharge of a shotgun, while he, Steven and William Ferrand were returning from a hunting trip. At that moment, legal title to the car was in Richard Doherty, conditional vendor. The right to possession was vested in A. E. Ferrand, conditional vendee. Ferrand was uninsured. The Motor Vehicle Department was not notified of the conditional sale by Doherty to Ferrand. The legal registration was not changed, Doherty retained title and remained personally liable to the bank for mortgage payments on the car. When the conditional sale was made, Doherty maintained an insurance policy on the car with Transnational. Thereafter, he allowed the policy to lapse. However, before the accident happened, Doherty reinstated that policy since he was apprehensive that Ferrand may not have purchased insurance coverage. These facts are not in dispute. A material circumstance attending the reinstatement of Transnational’s policy is in dispute, however. Doherty asserts that he fully advised the Transnational agent of the conditional sale to Ferrand at the time he reinstated the policy. The agent denies this assertion of fact. Accordingly, it is the position of the appellant Vigoren that a genuine issue of material fact exists which must be resolved by trial and precludes summary judgment.
1. For the purposes of summary judgment we must accept Doherty’s statement that Transnational was aware of the conditional sale to Ferrand when it reinstated the policy. This is a material fact bearing upon waiver. Transnational may not rely upon the change of beneficial ownership of the car to defeat coverage if it had knowledge of the conditional sale when it elected to reinstate the policy and receive a premium therefor. Such knowledge and reinstatement of the policy in spite of it, is a waiver of the right to rely upon the precise wording of the omnibus clause of that policy. Cf. Violin v. Fireman’s Fund Ins. Co., 81 Nev. 456, 406 P.2d 287 (1965). For this reason alone the summary judgment must be reversed and this issue of material fact submitted for resolution at trial. If the trier of facts finds that the Transnational agent did not *813know of the conditional sale to Ferrand, further legal questions of coverage will emerge and must then be resolved.
2. Waiver is an affirmative defense. NRCP 8(c). Of the named defendants, only Robert Vigoren appeared and he did not plead that defense. This is understandable since he cannot be presumed to have known of the disputed circumstances attending the reinstatement of Doherty’s insurance policy. Those disputed circumstances now appear of record and trial has not occurred. We direct the district court to allow Vigoren to amend his answer accordingly.
Reversed and remanded for trial.
Collins, C. J., Batjer and Mowbray, JJ., concur.Hartford Accident and Indemnity Company was permitted to intervene in the action since it had issued an automobile policy to the father of Robert Vigoren which policy provided uninsured motorist coverage. The summary judgment which we here review did not directly concern Hartford.