  We show that the shuffle $L \unicode{x29E2} F$ of a piecewise-testable
language $L$ and a finite language $F$ is piecewise-testable. The proof relies
on a classic but little-used automata-theoretic characterization of
piecewise-testable languages. We also discuss some mild generalizations of the
main result, and provide bounds on the piecewise complexity of $L
\unicode{x29E2} F$.
