diff --git a/structures.h b/structures.h
index 264317f..3b529ff 100644
--- a/structures.h
+++ b/structures.h
@@ -373,6 +373,7 @@ void message_remove_tree (struct message *M);
 void message_add_peer (struct message *M);
 void message_del_peer (struct message *M);
 void free_message (struct message *M);
+void message_del_use (struct message *M);
 
 #define PEER_USER 1
 #define PEER_CHAT 2