diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortChain.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortChain.java
index 2906411..c431c7a 100644
--- a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortChain.java
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/PortChain.java
@@ -16,7 +16,6 @@
 package org.onosproject.vtnrsc;
 
 import java.util.List;
-import java.util.Optional;
 import java.util.Set;
 
 import org.onosproject.net.DeviceId;
@@ -74,6 +73,13 @@
     List<FlowClassifierId> flowClassifiers();
 
     /**
+     * Returns the old port chain.
+     *
+     * @return old port chain
+     */
+    PortChain oldPortChain();
+
+    /**
      * Adds a new load balanced path.
      *
      * @param fiveTuple five tuple from the packet
@@ -182,7 +188,7 @@
      * @param path load balanced path
      * @return load balance id if the path matches, null otherwise.
      */
-    Optional<LoadBalanceId> matchPath(List<PortPairId> path);
+    LoadBalanceId matchPath(List<PortPairId> path);
 
     /**
      * Returns whether this port chain is an exact match to the port chain given