Remainder of polynomial long division in polynom doesn't include the last coefficient

Question

The polynom package for the long division of polynomials does not always get the remainder right.

\documentclass{minimal}

\usepackage{polynom}

\begin{document}

$$\polylongdiv{x^3+1}{x^2+1}$$

$$\polylongdiv{x^3+x^0}{x^2+1}$$

\end{document}

The remainder ought to be $-x+1$, not $-x$. How can I go about correcting this example?