It is obvious that the clone $\operatorname{Pol}\{f^\square\}$ is both a maximal clone and a primitive-positive clone if $f$ is a constant unary map, a regular permutation or $f(x,y,z)=x-y+z$ for some $p$-elementary Abelian group $(A,+,-,0)$, $p$-prime. In this paper we show that other maximal clones are not primitive-positive clones.