The zero-pinning (ZP) was proposed by Tay as a simple technique to design orthonormal wavelets by specifying certain zeros (local minima) of a Bernstein polynomial. It was shown by Yu and Baradarani that there can be problems with this technique in situations where certain local maxima (which are not specified) exceed the value 1, thus violating the nonnegativity condition required for orthonormal filters. We present some practical rules to avoid these situations.