diff --git a/hsarback/src/de/hsadmin/pillar/JsonPillarServlet.java b/hsarback/src/de/hsadmin/pillar/JsonPillarServlet.java
index 4f88ff4..5bfbc58 100644
--- a/hsarback/src/de/hsadmin/pillar/JsonPillarServlet.java
+++ b/hsarback/src/de/hsadmin/pillar/JsonPillarServlet.java
@@ -2,9 +2,10 @@ package de.hsadmin.pillar;
 
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
 
 import javax.persistence.EntityManager;
 import javax.persistence.Query;
@@ -49,7 +50,7 @@ public class JsonPillarServlet extends HttpServlet {
 		hiveQuery.setParameter("hive", hiveName);
 		final Object hiveResult = hiveQuery.getSingleResult();
 		final Hive hive = (Hive) hiveResult;
-		final List<String> dnsZones = new ArrayList<String>();
+		final Set<String> dnsZones = new TreeSet<String>();
 		final Query pacsQuery = em.createQuery("SELECT p FROM Pacs p WHERE p.hive.name = :hive AND p.basepac.name = 'PAC/WEB'");
 		pacsQuery.setParameter("hive", hiveName);
 		final List<?> pacsResult = pacsQuery.getResultList();