Stability of the internal n = 1 kink mode in tokamak depends strongly on the ellipticity and triangularity of the plasma cross-section at q = 1 surface. Penetration of the plasma shaping from the edge to the centrally localised q = 1 surface has been investigated numerically using the equilibrium code HELENA [1] for q - profiles close to the Bussac equilibrium and for a more realistic scenario with a flatter q - profile. The internal n = 1 kink mode growth rates are computed by the Ideal MHD MISHKA-1 code [2] for the equilibria considered. Plasma shaping optimal for the kink stability is discussed.