diff --git a/rw_core/coreIf/device_manager_if.go b/rw_core/coreIf/device_manager_if.go
index c8e33c1..dbe5598 100644
--- a/rw_core/coreIf/device_manager_if.go
+++ b/rw_core/coreIf/device_manager_if.go
@@ -24,4 +24,5 @@
 // DeviceManager represents a generic device manager
 type DeviceManager interface {
 	GetDevice(string) (*voltha.Device, error)
+	IsRootDevice(string) (bool, error)
 }