I agree that the preliminary injunction should be modified to the extent of excluding from its scope those clients of the plaintiff who had been brought into the firm by the defendant and his father when they joined it, and those clients which the defendant himself thereafter brought into the firm. Special Term was clearly correct in the conclusion that the noncom-petition clause in issue is on its face narrowly drawn, and one that in the usual situation would be enforceable. The problem arises from the undoubted fact that enforcement of the clause in accordance with its terms against this defendant will cause him very serious economic damage. The defendant is a lifelong resident of Baltimore who has practiced accounting in that city all his professional life. It is clear that he was required to withdraw from plaintiff firm because of dissatisfaction with his performance. To deny defendant the right to service those clients who had been developed over many years by his father and himself is to inflict on him a grievous professional injury indeed. I appreciate that it has been strongly argued that undue hardship is not a circumstance that may appropriately be relied upon to render invalid a noncompetition agreement that would otherwise be valid. (See Handler and Lazaroff, Restraint of Trade and the Restatement [Second] of Contracts, 57 NYU L Rev 669, 717-739; but cf. Restatement, Contracts 2d, § 188, subd [1], par [b].) But that issue appears not to have been definitively resolved in this State, and I see no reason for our deciding it at this stage of the litigation. Whatever conclusion may ultimately be reached after a trial, it seems to me that a balancing of the equities here clearly weighs against the issuance of a preliminary injunction to the extent to which it denies the defendant the right to serve what are in effect his clients. As to all other clients of the plaintiff firm, I agree that there is no valid reason not to sustain the injunction that was issued.