diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index b5562ab..ccad6c1 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -739,6 +739,9 @@
 
 	BT_DBG("conn %p", conn);
 
+	if (!(conn->hcon->link_mode & HCI_LM_MASTER))
+		return SMP_CMD_NOTSUPP;
+
 	hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req);
 
 	if (smp_ltk_encrypt(conn, hcon->pending_sec_level))