diff --git a/protocol.h b/protocol.h
index c22f94b..c948e80 100644
--- a/protocol.h
+++ b/protocol.h
@@ -87,6 +87,12 @@
 	} req;
 };
 
+struct protocol_close {
+	struct {
+		uint8_t flags;
+	} req;
+};
+
 struct protocol_ops {
 	int (*reset)(struct mbox_context *context);
 	int (*get_info)(struct mbox_context *context,
@@ -99,6 +105,7 @@
 			  struct protocol_mark_dirty *io);
 	int (*erase)(struct mbox_context *context, struct protocol_erase *io);
 	int (*flush)(struct mbox_context *context, struct protocol_flush *io);
+	int (*close)(struct mbox_context *context, struct protocol_close *io);
 };
 
 int protocol_init(struct mbox_context *context);
@@ -117,6 +124,7 @@
 int protocol_v1_mark_dirty(struct mbox_context *context,
 			   struct protocol_mark_dirty *io);
 int protocol_v1_flush(struct mbox_context *context, struct protocol_flush *io);
+int protocol_v1_close(struct mbox_context *context, struct protocol_close *io);
 
 /* Protocol v2 */
 int protocol_v2_get_info(struct mbox_context *context,
@@ -130,5 +138,6 @@
 int protocol_v2_erase(struct mbox_context *context,
 		      struct protocol_erase *io);
 int protocol_v2_flush(struct mbox_context *context, struct protocol_flush *io);
+int protocol_v2_close(struct mbox_context *context, struct protocol_close *io);
 
 #endif /* PROTOCOL_H */