diff --git a/src/libs/libmodinv/gauden.c b/src/libs/libmodinv/gauden.c
index 789c70fc..b5b42c7a 100644
--- a/src/libs/libmodinv/gauden.c
+++ b/src/libs/libmodinv/gauden.c
@@ -80,6 +80,8 @@ static float32 min_var = 1e38;	/* just a big num */
 
 #if defined (_WIN32)
 #define finite(x)    _finite(x)
+#else
+#define finite(x)    isfinite(x)
 #endif