diff --git a/subsys/bluetooth/host/smp.c b/subsys/bluetooth/host/smp.c
index f8b32a1188b..6c9fa43289a 100644
--- a/subsys/bluetooth/host/smp.c
+++ b/subsys/bluetooth/host/smp.c
@@ -616,7 +616,7 @@ static u8_t get_encryption_key_size(struct bt_smp *smp)
 /* Check that if a new pairing procedure with an existing bond will not lower
  * the established security level of the bond.
  */
-bool update_keys_check(struct bt_smp *smp)
+static bool update_keys_check(struct bt_smp *smp)
 {
 	struct bt_conn *conn = smp->chan.chan.conn;