diff --git a/Include/pyport.h b/Include/pyport.h
index f635703..dceb98d 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -281,6 +281,8 @@
 /* If the fd manipulation macros aren't defined,
    here is a set that should do the job */
 
+#ifdef 0 /* disabled and probably obsolete */
+
 #ifndef	FD_SETSIZE
 #define	FD_SETSIZE	256
 #endif
@@ -304,6 +306,9 @@
 #define FD_ZERO(p)	memset((char *)(p), '\0', sizeof(*(p)))
 
 #endif /* FD_SET */
+
+#endif /* fd manipulation macros */
+
 #ifdef __cplusplus
 }
 #endif