diff --git a/src/main/java/org/gcube/accounting/analytics/persistence/couchbase/AccountingPersistenceQueryCouchBase.java b/src/main/java/org/gcube/accounting/analytics/persistence/couchbase/AccountingPersistenceQueryCouchBase.java
index 28692fb..d161965 100644
--- a/src/main/java/org/gcube/accounting/analytics/persistence/couchbase/AccountingPersistenceQueryCouchBase.java
+++ b/src/main/java/org/gcube/accounting/analytics/persistence/couchbase/AccountingPersistenceQueryCouchBase.java
@@ -807,7 +807,7 @@ public class AccountingPersistenceQueryCouchBase implements AccountingPersistenc
 	 * @return SortedSet
 	 * @throws Exception
 	 */
-	public SortedSet<NumberedFilter> getNextPossibleValuesWithMap(Class<? extends AggregatedRecord<?,?>> clz,
+	protected SortedSet<NumberedFilter> getNextPossibleValuesWithMap(Class<? extends AggregatedRecord<?,?>> clz,
 			TemporalConstraint temporalConstraint, List<Filter> filters, String key, String orderingProperty)
 			throws Exception {
 		
@@ -978,8 +978,7 @@ public class AccountingPersistenceQueryCouchBase implements AccountingPersistenc
 	 * @return SortedSet
 	 * @throws Exception
 	 */
-	@Override
-	public SortedSet<NumberedFilter> getNextPossibleValues(Class<? extends AggregatedRecord<?,?>> clz,
+	private SortedSet<NumberedFilter> getNextPossibleValues(Class<? extends AggregatedRecord<?,?>> clz,
 			TemporalConstraint temporalConstraint, List<Filter> filters, String key, String orderingProperty)
 			throws Exception {