diff --git a/visualc/include/ngspice/config.h b/visualc/include/ngspice/config.h
index 6ad59ad55..83f138895 100644
--- a/visualc/include/ngspice/config.h
+++ b/visualc/include/ngspice/config.h
@@ -89,6 +89,17 @@
 /* Define to 1 if you have the <ctype.h> header file. */
 #define HAVE_CTYPE_H 1
 
+/* Define to 1 if you have the declaration of `isinf', and to 0 if you don't.
+   */
+#define HAVE_DECL_ISINF 1
+
+/* Define to 1 if you have the declaration of `isnan', and to 0 if you don't.
+   */
+#define HAVE_DECL_ISNAN 1
+
+/* Define to 1 if you have the `finite' function. */
+#define HAVE_FINITE 1
+
 /* Define to 1 if you have the declaration of `tzname', and to 0 if you don't.
    */
 /* #undef HAVE_DECL_TZNAME */