diff --git a/plugins/calendar/drivers/kolab/SQL/postgres.initial.sql b/plugins/calendar/drivers/kolab/SQL/postgres.initial.sql
new file mode 100644
index 00000000..10b4ac40
--- /dev/null
+++ b/plugins/calendar/drivers/kolab/SQL/postgres.initial.sql
@@ -0,0 +1,31 @@
+/**
+ * Roundcube Calendar Kolab backend
+ *
+ * @version @package_version@
+ * @author Thomas Bruederli
+ * @licence GNU AGPL
+ **/
+
+CREATE TABLE IF NOT EXISTS kolab_alarms (
+  event_id character varying(255) NOT NULL,
+  user_id integer NOT NULL
+        REFERENCES users (user_id) ON DELETE CASCADE ON UPDATE CASCADE,
+  notifyat timestamp without time zone DEFAULT NULL,
+  dismissed smallint NOT NULL DEFAULT 0,
+  PRIMARY KEY(event_id)
+);
+
+CREATE TABLE IF NOT EXISTS itipinvitations (
+  token character varying(64) NOT NULL,
+  event_uid character varying(255) NOT NULL,
+  user_id integer NOT NULL
+        REFERENCES users (user_id) ON DELETE CASCADE ON UPDATE CASCADE,
+  event text NOT NULL,
+  expires timestamp without time zone DEFAULT NULL,
+  cancelled smallint NOT NULL DEFAULT 0,
+  PRIMARY KEY(token)
+);
+
+CREATE INDEX itipinvitations_event_uid_user_id_idx ON itipinvitations (event_uid, user_id);
+
+INSERT INTO system (name, value) VALUES ('calendar-kolab-version', '2013011000');