Underscore in a pragma breaks the lhs2tex-generated LaTeX code

pragmabug

\documentclass{article}
%include lhs2TeX.fmt
%include lhs2TeX.sty
%include polycode.fmt
\begin{document}

\begin{code}
module Equal where

data _≡_ {a} {A : Set a} (x : A) : A → Set a where
  refl : x ≡ x

{-# BUILTIN EQUALITY _≡_ #-}
\end{code}
\end{document}