$NetBSD$

--- diag.c.orig	1999-11-23 00:07:31.000000000 +0000
+++ diag.c
@@ -125,8 +125,10 @@ extern int diagnostics;
 extern struct st_host_info hinfo[];
 extern int initial_diagnostics;
 extern int screen;
+#if !defined(__NetBSD__) && !defined(__DragonFly__) && !defined(__FreeBSD__)
 extern int sys_nerr;
-#if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__GNU_LIBRARY__) && !defined(__GLIBC__) && !defined(__EMX__)
+#endif
+#if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__GNU_LIBRARY__) && !defined(__GLIBC__) && !defined(__EMX__) && !defined(__DragonFly__)
 extern char *sys_errlist[];
 #endif
 
