diff --git a/samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf b/samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf
index 3377273dd9a..8fbd3d3af2d 100644
--- a/samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf
+++ b/samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf
@@ -9,6 +9,9 @@ CONFIG_IPC_SERVICE_BACKEND_RPMSG_WQ_STACK_SIZE=512
 CONFIG_HEAP_MEM_POOL_SIZE=8192
 CONFIG_CBPRINTF_REDUCED_INTEGRAL=y
 
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y
+CONFIG_LTO=y
+
 CONFIG_BT=y
 CONFIG_BT_HCI_RAW=y
 CONFIG_BT_MAX_CONN=2