diff --git a/autoopts/tpl/texi2mdoc.sh b/autoopts/tpl/texi2mdoc.sh

index 4aff400..60eb43c 100755

--- a/autoopts/tpl/texi2mdoc.sh

+++ b/autoopts/tpl/texi2mdoc.sh

@@ -33,8 +33,9 @@

 # /bin/sh on Solaris is too horrible for words

 #

+XPG4_SH=/usr/xpg4/bin/sh

 case "$0" in

-/bin/sh ) test -x /usr/xpg4/bin/sh && exec /usr/xpg4/bin/sh ${1+"$@"} ;;

+/bin/sh ) test -x $XPG4_SH && exec $XPG4_SH ${1+"$@"} ;;

 esac

 parent_pid=$$