diff --git a/dba/caldav_functions.sql b/dba/caldav_functions.sql
index 10975e91..580fd508 100644
--- a/dba/caldav_functions.sql
+++ b/dba/caldav_functions.sql
@@ -236,7 +236,8 @@ BEGIN
 
   SELECT rt1.confers INTO out_confers, tmp_confers FROM relationship r1 JOIN relationship_type rt1 ON ( r1.rt_id = rt1.rt_id )
               LEFT OUTER JOIN relationship r2 ON ( rt1.rt_id = r2.rt_id )
-   WHERE rt1.rt_isgroup AND r1.from_user = in_from AND r2.from_user = in_to AND r1.from_user != r2.from_user AND r1.to_user = r2.to_user;
+   WHERE rt1.rt_isgroup AND r1.from_user = in_from AND r2.from_user = in_to AND r1.from_user != r2.from_user AND r1.to_user = r2.to_user
+     AND NOT EXISTS( SELECT 1 FROM relationship r3 WHERE r3.from_user = r1.to_user ) ;
 
   IF FOUND THEN
     -- dbg := ''H-'';