Stability of functional equations has recent applications in many fields. We show that the stability results obtained by J. Brzdęk and concerning the functional equation of the p-Wright affine function: f (px 1 + (1 − p)x 2) + f ((1 − p)x 1 + px 2) = f (x 1) + f (x 2), can be proved also in (2,α)-Banach spaces, for some real number α ∈ (0, 1). This is done using some fixed-point theorem.