--- /dev/null
+--- a/sysdep/unix/krt.h
++++ b/sysdep/unix/krt.h
+@@ -112,7 +112,7 @@ struct kif_proto {
+ struct kif_state sys; /* Sysdep state */
+ };
+
+-struct kif_proto *kif_proto;
++extern struct kif_proto *kif_proto;
+
+ #define KIF_CF ((struct kif_config *)p->p.cf)
+