$OpenBSD$
--- include/osg/Math.orig	Tue Mar  2 16:40:35 2010
+++ include/osg/Math	Tue Mar  2 16:41:05 2010
@@ -212,8 +212,8 @@ inline double round(double v) { return v>=0.0?floor(v+
         inline bool isNaN(double v) { return std::isnan(v); }
     #else
         // Need to use to std::isnan to avoid undef problem from <cmath>
-        inline bool isNaN(float v) { return isnan(v); }
-        inline bool isNaN(double v) { return isnan(v); }
+        inline bool isNaN(float v) { return __isnanf(v); }
+        inline bool isNaN(double v) { return __isnanf(v); }
     #endif
 #endif