\makeatletter \renewenvironment{theindex} {\pagestyle{plain}\parindent\z@ \parskip\z@ \@plus .3\p@\relax \let\item\@idxitem} {\thispagestyle{plain}} \makeatother \begin{multicols}{3}[\chapter*{Index}\addcontentsline{toc}{chapter}{Index}] \printindex \end{multicols}