1 files changed, 1 insertions, 1 deletions

diff --git a/proto.h b/proto.h
index 7a4b23a..227a748 100644
--- a/proto.h
+++ b/proto.h
@@ -17,7 +17,7 @@ struct pkt_buff;
 
 struct protocol {
 	/* Needs to be filled out by user */
-	unsigned int key;
+	const unsigned int key;
 	void (*print_full)(struct pkt_buff *pkt);
 	void (*print_less)(struct pkt_buff *pkt);
 	/* Used by program logic */