diff --git a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/cli/subnet/SubnetUpdateCommand.java b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/cli/subnet/SubnetUpdateCommand.java
index 2e8fc20..f8ee6b9 100644
--- a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/cli/subnet/SubnetUpdateCommand.java
+++ b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/cli/subnet/SubnetUpdateCommand.java
@@ -88,11 +88,11 @@
 
     @Option(name = "-h", aliases = "--hostRoutes", description = "Subnet jsonnode hostRoutes",
             required = false, multiValued = false)
-    Iterable<HostRoute> hostRoutes = null;
+    Set<HostRoute> hostRoutes = Sets.newHashSet();
 
     @Option(name = "-a", aliases = "--allocationPools",
             description = "Subnet jsonnode allocationPools", required = false, multiValued = false)
-    Iterable<AllocationPool> allocationPools = Sets.newHashSet();;
+    Set<AllocationPool> allocationPools = Sets.newHashSet();;
 
     @Override
     protected void execute() {