diff --git a/net/ceph/auth.c b/net/ceph/auth.c
index 78067dda9d3c..53aa2d27e36b 100644
--- a/net/ceph/auth.c
+++ b/net/ceph/auth.c
@@ -114,7 +114,7 @@ int ceph_auth_build_hello(struct ceph_auth_client *ac, void *buf, size_t len)
 	monhdr->session_mon = cpu_to_le16(-1);
 	monhdr->session_mon_tid = 0;
 
-	ceph_encode_32(&p, 0);  /* no protocol, yet */
+	ceph_encode_32(&p, CEPH_AUTH_UNKNOWN);  /* no protocol, yet */
 
 	lenp = p;
 	p += sizeof(u32);