For each r ∈ N we prove the Nikolskii type pointwise estimate for coconvex approximation of functions f ∈ W , the subspace of all functions f ∈ C[−1, 1], possessing an absolutely continuous (r−1)st derivative on (−1, 1) and satisfying f (r) ∈ L∞[−1, 1], that change their convexity once on [−1, 1].