Environment abstract missing from bfhthesis

In 1.5.0, the abstract environment is missing. I assume it is since switching to scrbook as base class for bfhthesis (69215ae4).

Sample document:

\documentclass{bfhthesis}

\title{Thesis}
\author{Max Musterman}
\degreeprogramme{Program}
\advisor{Hans}
\coadvisor{Brigitte}
\expert{Michel}
\projectpartner{Some company}

\begin{document}
\maketitle

\begin{abstract}
test
\end{abstract}
\end{document}