killbill-memoizeit

diff --git a/api/src/main/java/com/ning/billing/catalog/api/BillingPeriod.java b/api/src/main/java/com/ning/billing/catalog/api/BillingPeriod.java
index aa8b20c..7d129af 100644
--- a/api/src/main/java/com/ning/billing/catalog/api/BillingPeriod.java
+++ b/api/src/main/java/com/ning/billing/catalog/api/BillingPeriod.java
@@ -20,8 +20,9 @@ public enum BillingPeriod {
 	MONTHLY(1),
 	QUARTERLY(3),
 	//SEMI_ANNUAL(6), ** not yet supported
-	ANNUAL(12);
+	ANNUAL(12),
 	//BI_ANNUAL(24); ** not yet supported
+	NO_BILLING_PERIOD(0);
 
     private final int numberOfMonths;
 

diff --git a/catalog/src/main/java/com/ning/billing/catalog/PlanPhase.java b/catalog/src/main/java/com/ning/billing/catalog/PlanPhase.java
index 3f43e5f..6d9630b 100644
--- a/catalog/src/main/java/com/ning/billing/catalog/PlanPhase.java
+++ b/catalog/src/main/java/com/ning/billing/catalog/PlanPhase.java
@@ -40,7 +40,7 @@ public class PlanPhase extends ValidatingConfig<Catalog> implements IPlanPhase {
     private Duration duration;
     
     @XmlElement(required=false)
-    private BillingPeriod billingPeriod;
+    private BillingPeriod billingPeriod = BillingPeriod.NO_BILLING_PERIOD;
 
 	@XmlElement(required=false)
 	private InternationalPrice recurringPrice;