diff --git a/zebra/kernel_socket.h b/zebra/kernel_socket.h
index 8f8a207..e9558ad 100644
--- a/zebra/kernel_socket.h
+++ b/zebra/kernel_socket.h
@@ -28,6 +28,6 @@
 extern int ifm_read (struct if_msghdr *);
 extern int rtm_write (int, union sockunion *, union sockunion *,
                       union sockunion *, unsigned int, int, int);
-extern struct message rtm_type_str[];
+extern const struct message rtm_type_str[];
 
 #endif /* __ZEBRA_KERNEL_SOCKET_H */