diff --git a/inc/medleyfp.h b/inc/medleyfp.h
index 5a18518..34f671f 100755
--- a/inc/medleyfp.h
+++ b/inc/medleyfp.h
@@ -106,7 +106,7 @@ volatile extern int  FP_error;
 
 #elif defined(MACOSX) || defined(FREEBSD)
 #define FPCLEAR
-#define FPTEST(result) (!finite(result))
+#define FPTEST(result) (!isfinite(result))
 
 #elif defined(DOS)
 #define FPCLEAR