--- src/Make2.g++.orig	2009-02-02 07:39:11.000000000 +0100
+++ src/Make2.g++	2009-07-25 14:35:54.000000000 +0200
@@ -26,6 +26,7 @@
 CCC = g++
 
 CCFLAGS = \
+-DNEEDS_IS_INF -DNEEDS_IS_NAN \
 -DHAVE_LIBREADLINE \
 -DUNIX -O2 -DNDEBUG -I.. -I. -W