diff --git a/wireless/bluetooth/bt_ioctl.c b/wireless/bluetooth/bt_ioctl.c
index ff59932e80..486ce83b3b 100644
--- a/wireless/bluetooth/bt_ioctl.c
+++ b/wireless/bluetooth/bt_ioctl.c
@@ -477,7 +477,7 @@ int btnet_ioctl(FAR struct net_driver_s *netdev, int cmd, unsigned long arg)
   FAR struct btreq_s *btreq = (FAR struct btreq_s *)((uintptr_t)arg);
   int ret;
 
-  wlinfo("cmd=%04x arg=%ul\n", cmd, arg);
+  wlinfo("cmd=%04x arg=%lu\n", cmd, arg);
   DEBUGASSERT(netdev != NULL && netdev->d_private != NULL);
 
   if (btreq == NULL)