diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index 53568a6..06d22a3 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -395,11 +395,11 @@
 /* Define to 1 if you have the `copysign' function. */
 #define HAVE_COPYSIGN 1
 
-/* Define to 1 if you have the `isinf' function. */
-#define HAVE_ISINF 1
+/* Define to 1 if you have the `isinf' macro. */
+#define HAVE_DECL_ISINF 1
 
 /* Define to 1 if you have the `isnan' function. */
-#define HAVE_ISNAN 1
+#define HAVE_DECL_ISNAN 1
 
 /* Define if on AIX 3.
    System headers sometimes define this.