Listings package: how to suppress highlighting/emphasis on identifiers containing keywords?

Question

I'm using the x86masm dialect of Assembler and register names are emphasized even when they occur inside of a label or a hexadecimal number. For example, dh is register, but 0dh is a number, yet the dh part of it is emphasized. I haven't had this problem in listings with any other languages, so I'm assuming it's a problem with the language definition. Is there simple way to redefine the language so that this doesn't happen?

\documentclass[12pt]{article}
\usepackage{courier, listings}

\lstset{
  language={[x86masm]Assembler},
  basicstyle=\ttfamily\small,
  frame=single
}

\begin{document}
\begin{lstlisting}
cmp al, 0dh ; dh = register, 0dh = number
je somewhere
\end{lstlisting}

\end{document}

Answer 1

use deletekeywords=.... However, you should use another monotypefont like beramono. Courier is not a good looking mono font.

\documentclass[12pt]{article}
\usepackage{courier, listings}

\lstset{
  language={[x86masm]Assembler},
  basicstyle=\ttfamily\small,
  frame=single,
  deletekeywords={dh}
}

\begin{document}
\begin{lstlisting}
cmp al, 0dh ; dh = register, 0dh = number
je somewhere
\end{lstlisting}

\end{document}