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 a5a2a90..63971b9 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
@@ -62,8 +62,8 @@
     }
 
     @Override
-    public boolean markOnline(DeviceId deviceId) {
-        return false;
+    public DeviceEvent markOnline(DeviceId deviceId) {
+        return null;
     }
 
     @Override