killbill-memoizeit

diff --git a/subscription/src/main/java/org/killbill/billing/subscription/engine/dao/DefaultSubscriptionDao.java b/subscription/src/main/java/org/killbill/billing/subscription/engine/dao/DefaultSubscriptionDao.java
index c139cc9..03e813e 100644
--- a/subscription/src/main/java/org/killbill/billing/subscription/engine/dao/DefaultSubscriptionDao.java
+++ b/subscription/src/main/java/org/killbill/billing/subscription/engine/dao/DefaultSubscriptionDao.java
@@ -947,7 +947,9 @@ public class DefaultSubscriptionDao extends EntityDaoBase<SubscriptionBundleMode
                     }
                 }
                 // Set total ordering value of the fake dryRun event to make sure billing events are correctly ordererd
-                curDryRun.setTotalOrdering(events.get(events.size() - 1).getTotalOrdering() + 1);
+                if (!events.isEmpty()) {
+                    curDryRun.setTotalOrdering(events.get(events.size() - 1).getTotalOrdering() + 1);
+                }
                 events.add(curDryRun);
             }
         }