diff --git a/dba/patches/1.1.9.sql b/dba/patches/1.1.9.sql
new file mode 100644
index 00000000..056cd100
--- /dev/null
+++ b/dba/patches/1.1.9.sql
@@ -0,0 +1,13 @@
+
+-- Adding a primary key to the calendar_item table
+
+BEGIN;
+SELECT check_db_revision(1,1,8);
+
+ALTER TABLE calendar_item ADD PRIMARY KEY (user_no, dav_name );
+
+SELECT new_db_revision(1,1,9, 'September' );
+COMMIT;
+ROLLBACK;
+
+VACUUM FULL ANALYZE;
\ No newline at end of file
diff --git a/dba/rscds.sql b/dba/rscds.sql
index 364eee7b..2e76a617 100644
--- a/dba/rscds.sql
+++ b/dba/rscds.sql
@@ -59,7 +59,9 @@ CREATE TABLE calendar_item (
   -- Cascade updates / deletes from the caldav_data table
   CONSTRAINT caldav_exists FOREIGN KEY ( user_no, dav_name )
                 REFERENCES caldav_data ( user_no, dav_name )
-                MATCH FULL ON DELETE CASCADE ON UPDATE CASCADE DEFERRABLE
+                MATCH FULL ON DELETE CASCADE ON UPDATE CASCADE DEFERRABLE,
+
+  PRIMARY KEY ( user_no, dav_name )
 );
 
 GRANT SELECT,INSERT,UPDATE,DELETE ON calendar_item TO general;
@@ -139,4 +141,4 @@ CREATE TABLE freebusy_ticket (
 
 GRANT INSERT,SELECT,UPDATE,DELETE ON TABLE freebusy_ticket TO general;
 
-SELECT new_db_revision(1,1,8, 'August' );
+SELECT new_db_revision(1,1,9, 'September' );