diff --git a/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbMastershipService.java b/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbMastershipService.java
index 34b8cd9..8d2a48f 100644
--- a/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbMastershipService.java
+++ b/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbMastershipService.java
@@ -19,11 +19,11 @@
 import com.google.common.annotations.Beta;
 import io.grpc.BindableService;
 import io.grpc.stub.StreamObserver;
-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.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.onosproject.cluster.NodeId;
 import org.onosproject.cluster.RoleInfo;
 import org.onosproject.grpc.nb.mastership.MastershipServiceGrpc;
@@ -57,10 +57,10 @@
 
     private final Logger log = getLogger(getClass());
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
     protected GrpcServiceRegistry registry;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
     protected MastershipService mastershipService;
 
     private MastershipServiceNbServerInternal instance = null;