diff --git a/configure.in b/configure.in
index 5e19f65..0633e3d 100644
--- a/configure.in
+++ b/configure.in
@@ -13,28 +13,28 @@ AC_SUBST(AUTHORS)
 AC_DEFINE_UNQUOTED(AUTHORS, "$AUTHORS")
 
 dnl# Find RCS Ident info from source files
-AC_DEFINE_UNQUOTED(ACTIONS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(BUTTONS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(COMMAND_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(DRAW_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(E_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(EVENTS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(FONT_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(GRKELOT_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(MAIN_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(MENUS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(MISC_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(NETDISP_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(OPTIONS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(PIXMAP_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(SCREEN_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(SCROLLBAR_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(STARTUP_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(SYSTEM_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(TERM_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(TIMER_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(UTMP_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
-AC_DEFINE_UNQUOTED(WINDOWS_IDENT, "`grep '$Id$Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(ACTIONS_IDENT, "`grep '$''Id:' src/actions.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(BUTTONS_IDENT, "`grep '$''Id:' src/buttons.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(COMMAND_IDENT, "`grep '$''Id:' src/command.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(DRAW_IDENT, "`grep '$''Id:' src/draw.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(E_IDENT, "`grep '$''Id:' src/e.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(EVENTS_IDENT, "`grep '$''Id:' src/events.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(FONT_IDENT, "`grep '$''Id:' src/font.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(GRKELOT_IDENT, "`grep '$''Id:' src/grkelot.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(MAIN_IDENT, "`grep '$''Id:' src/main.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(MENUS_IDENT, "`grep '$''Id:' src/menus.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(MISC_IDENT, "`grep '$''Id:' src/misc.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(NETDISP_IDENT, "`grep '$''Id:' src/netdisp.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(OPTIONS_IDENT, "`grep '$''Id:' src/options.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(PIXMAP_IDENT, "`grep '$''Id:' src/pixmap.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(SCREEN_IDENT, "`grep '$''Id:' src/screen.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(SCROLLBAR_IDENT, "`grep '$''Id:' src/scrollbar.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(STARTUP_IDENT, "`grep '$''Id:' src/startup.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(SYSTEM_IDENT, "`grep '$''Id:' src/system.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(TERM_IDENT, "`grep '$''Id:' src/term.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(TIMER_IDENT, "`grep '$''Id:' src/timer.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(UTMP_IDENT, "`grep '$''Id:' src/utmp.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
+AC_DEFINE_UNQUOTED(WINDOWS_IDENT, "`grep '$''Id:' src/windows.c | sed 's/^.*\$''Id: //;s/ \$.*$//;s/.v / /;s/ Exp//'`")
 
 dnl# Supply default CFLAGS, if not specified by `CFLAGS=flags ./configure'
 if test ! -z "${CFLAGS}" -o ! -z "${CCOPTS}"; then