Index: rrdtool-1.4.3/src/rrd_format.h
===================================================================
--- rrdtool-1.4.3.orig/src/rrd_format.h
+++ rrdtool-1.4.3/src/rrd_format.h
@@ -35,7 +35,7 @@
 /* changed because microsecond precision requires another field */
 #define RRD_VERSION   "0004"
 #define RRD_VERSION3  "0003"
-#define FLOAT_COOKIE  8.642135E130
+#define FLOAT_COOKIE  ((double) 8.642135E130)
 
 typedef union unival {
     unsigned long u_cnt;