diff --git a/core/api/src/test/java/org/onosproject/net/device/DeviceStoreAdapter.java b/core/api/src/test/java/org/onosproject/net/device/DeviceStoreAdapter.java
index d13da6a..9859892 100644
--- a/core/api/src/test/java/org/onosproject/net/device/DeviceStoreAdapter.java
+++ b/core/api/src/test/java/org/onosproject/net/device/DeviceStoreAdapter.java
@@ -57,6 +57,11 @@
     }
 
     @Override
+    public boolean markOnline(DeviceId deviceId) {
+        return false;
+    }
+
+    @Override
     public DeviceEvent markOffline(DeviceId deviceId) {
         return null;
     }