diff --git a/source/java/org/alfresco/repo/security/authority/AuthorityDAOImpl.java b/source/java/org/alfresco/repo/security/authority/AuthorityDAOImpl.java
index a7dc9fa01a..bf294d6978 100644
--- a/source/java/org/alfresco/repo/security/authority/AuthorityDAOImpl.java
+++ b/source/java/org/alfresco/repo/security/authority/AuthorityDAOImpl.java
@@ -1019,7 +1019,7 @@ public class AuthorityDAOImpl implements AuthorityDAO, NodeServicePolicies.Befor
         NodeRef zoneRef = getZone(zoneName);
         if (zoneRef == null)
         {
-            Collections.emptySet();
+            return Collections.emptySet();
         }
         return new HashSet<String>(getAuthoritiesImpl(type, zoneRef, null, false, false, new PagingRequest(0, Integer.MAX_VALUE, null)).getPage());
     }
diff --git a/source/java/org/alfresco/repo/security/authority/GetAuthoritiesCannedQueryFactory.java b/source/java/org/alfresco/repo/security/authority/GetAuthoritiesCannedQueryFactory.java
index ab9bac5990..2fd3d4ed9f 100644
--- a/source/java/org/alfresco/repo/security/authority/GetAuthoritiesCannedQueryFactory.java
+++ b/source/java/org/alfresco/repo/security/authority/GetAuthoritiesCannedQueryFactory.java
@@ -90,26 +90,19 @@ public class GetAuthoritiesCannedQueryFactory extends AbstractCannedQueryFactory
     
     public CannedQuery<AuthorityInfo> getCannedQuery(AuthorityType type, NodeRef containerRef, String displayNameFilter, boolean sortByDisplayName, boolean sortAscending, PagingRequest pagingRequest)
     {
+        ParameterCheck.mandatory("containerRef", containerRef);
         ParameterCheck.mandatory("pagingRequest", pagingRequest);
         
-        if ((type == null) && (containerRef == null))
-        {
-            throw new IllegalArgumentException("Type and/or containerRef required - both cannot be null");
-        }
-        
         int requestTotalCountMax = pagingRequest.getRequestTotalCountMax();
         
-        Long containerNodeId = null;
-        if (containerRef != null)
+        Pair<Long, NodeRef> nodePair = nodeDAO.getNodePair(tenantService.getName(containerRef));
+        if (nodePair == null)
         {
-            Pair<Long, NodeRef> nodePair = nodeDAO.getNodePair(tenantService.getName(containerRef));
-            if (nodePair == null)
-            {
-                throw new InvalidNodeRefException("Container ref does not exist: " + containerRef, containerRef);
-            }
-            containerNodeId = nodePair.getFirst();
+            throw new InvalidNodeRefException("Container ref does not exist: " + containerRef, containerRef);
         }
         
+        Long containerNodeId = nodePair.getFirst();
+        
         // specific query params
         GetAuthoritiesCannedQueryParams paramBean = new GetAuthoritiesCannedQueryParams(type,
                                                                                         containerNodeId,