diff --git a/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java b/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
index 9edcc1c..fb1d4e4 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
@@ -15,18 +15,8 @@
  */
 package org.onosproject.store.device.impl;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import java.util.Optional;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicLong;
-
-import org.apache.felix.scr.annotations.Activate;
-import org.apache.felix.scr.annotations.Component;
-import org.apache.felix.scr.annotations.Deactivate;
-import org.apache.felix.scr.annotations.Reference;
-import org.apache.felix.scr.annotations.ReferenceCardinality;
-import org.apache.felix.scr.annotations.Service;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
 import org.onosproject.cluster.ClusterService;
 import org.onosproject.cluster.NodeId;
 import org.onosproject.mastership.MastershipEvent;
@@ -39,27 +29,34 @@
 import org.onosproject.net.device.DeviceClockService;
 import org.onosproject.store.Timestamp;
 import org.onosproject.store.impl.MastershipBasedTimestamp;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
 import org.slf4j.Logger;
 
-import com.google.common.cache.Cache;
-import com.google.common.cache.CacheBuilder;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.slf4j.LoggerFactory.getLogger;
 
 /**
  * Clock service to issue Timestamp based on Device Mastership.
  */
-@Component(immediate = true)
-@Service
+@Component(immediate = true, service = DeviceClockService.class)
 public class DeviceClockManager implements DeviceClockService {
 
     private final Logger log = getLogger(getClass());
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
     protected MastershipTermService mastershipTermService;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
     protected MastershipService mastershipService;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
     protected ClusterService clusterService;
 
     protected NodeId localNodeId;