--- fvwm-2.5.23/configure.ac.alt-configure-datarootdir	2007-09-12 09:48:06 +0400
+++ fvwm-2.5.23/configure.ac	2007-09-12 09:49:06 +0400
@@ -1660,6 +1660,9 @@ AC_SUBST(with_xrender)
 AC_SUBST(with_xpm)
 
 dnl with autoconf <2.60 this is needed
+if test "x$datarootdir" = "x"; then
+	datarootdir="$datadir"
+fi
 AC_SUBST(datarootdir)
 AC_SUBST(docdir)