Let $R:\mathbb{C}\to\mathbb{C}$ be a nonconstant polynomial. Then there exists $x\in(-\infty,0)$ such that $|R(x)|>1$. Consequently, no one-step method whose stability function is a nonconstant polynomial is A-stable, where A-stability means that the stability function is defined on the closed left half-plane and satisfies $|R(z)|\leq 1$ for every $z\in\mathbb{C}$ with $\operatorname{Re}(z)\leq 0$.