$NetBSD: patch-aj,v 1.1 2005/12/28 16:06:37 joerg Exp $

--- src/misc/missing_math.h.orig	2005-12-28 15:49:19.000000000 +0000
+++ src/misc/missing_math.h
@@ -20,7 +20,7 @@ double scalb(double, int);
 #  endif
 #endif
 
-#ifndef HAVE_ISNAN
+#if !defined(HAVE_ISNAN) && !defined(isnan)
 int isnan(double value);
 #endif /* HAVE_ISNAN */
 
