character in the PDF

Question

Here is my MWE:

\documentclass{scrartcl}
\usepackage{beramono}
\usepackage[T1]{fontenc}
\begin{document}
\begin{verbatim}
' only a test
\end{verbatim}
\end{document}

If I copy the text from the PDF viewer, the following characters are in the clipboard:

’ only a test

The apostrophe is different. What can I do, that in the PDF I can grab the original input character?