diff --git a/entitlement/src/main/java/com/ning/billing/entitlement/engine/dao/RepairEntitlementDao.java b/entitlement/src/main/java/com/ning/billing/entitlement/engine/dao/RepairEntitlementDao.java
index 2d1b530..45a9831 100644
--- a/entitlement/src/main/java/com/ning/billing/entitlement/engine/dao/RepairEntitlementDao.java
+++ b/entitlement/src/main/java/com/ning/billing/entitlement/engine/dao/RepairEntitlementDao.java
@@ -93,6 +93,14 @@ public class RepairEntitlementDao implements EntitlementDao, RepairEntitlementLi
this.events = new TreeSet<EntitlementEventWithOrderingId>(new Comparator<EntitlementEventWithOrderingId>() {
@Override
public int compare(final EntitlementEventWithOrderingId o1, final EntitlementEventWithOrderingId o2) {
+ // Work around jdk7 change: compare(o1, o1) is now invoked when inserting the first element
+ // See:
+ // - http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5045147
+ // - http://hg.openjdk.java.net/jdk7/tl/jdk/rev/bf37edb38fbb
+ if (o1 == o2) {
+ return 0;
+ }
+
final int result = o1.getEvent().getEffectiveDate().compareTo(o2.getEvent().getEffectiveDate());
if (result == 0) {
if (o1.getOrderingId() < o2.getOrderingId()) {
