diff --git a/rw_core/mocks/adapter_olt.go b/rw_core/mocks/adapter_olt.go
index b9cef0c..2ab98a3 100644
--- a/rw_core/mocks/adapter_olt.go
+++ b/rw_core/mocks/adapter_olt.go
@@ -256,3 +256,8 @@
 	}()
 	return nil
 }
+
+// Child_device_lost deletes ONU and its references
+func (oltA *OLTAdapter) Child_device_lost(deviceID string, pPortNo uint32, onuID uint32) error { // nolint
+	return nil
+}
diff --git a/rw_core/mocks/device_manager.go b/rw_core/mocks/device_manager.go
index 116c7dc..6edfdc9 100644
--- a/rw_core/mocks/device_manager.go
+++ b/rw_core/mocks/device_manager.go
@@ -176,3 +176,8 @@
 func (dm *DeviceManager) ProcessTransition(previous *voltha.Device, current *voltha.Device) error {
 	return nil
 }
+
+// ChildDeviceLost -
+func (dm *DeviceManager) ChildDeviceLost(ctx context.Context, cDevice *voltha.Device) error {
+	return nil
+}