(tex-mode): Allow for documentclass options when checking for SliTeX.

1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 00518f8578b..bec121b4100 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -262,7 +262,8 @@ says which mode to use."
                                     (search-forward "%" search-end t))))))
       (if (and slash (not comment))
           (setq mode (if (looking-at "documentstyle\\|documentclass")
-                         (if (looking-at "documentstyle{slides}\\|documentclass{slides}")
+                         (if (looking-at
+                              "document\\(style\\|class\\)\\(\\[.*\\]\\)?{slides}")
                              'slitex-mode
                            'latex-mode)
                        'plain-tex-mode))))