diff --git a/scripts/migration_timescaledb.sql b/scripts/migration_timescaledb.sql
index 0d2c28f..b5bf9a5 100644
--- a/scripts/migration_timescaledb.sql
+++ b/scripts/migration_timescaledb.sql
@@ -37,8 +37,11 @@ CREATE SEQUENCE public.messages2_id_seq
     NO MAXVALUE
     CACHE 1;
 
-ALTER TABLE messages2
+ALTER TABLE public.messages2
     ADD CONSTRAINT messages2_pkey PRIMARY KEY (id, "timestamp");
+ALTER TABLE public.messages2
+    ADD CONSTRAINT messages2_msg_id
+    UNIQUE (msg_id, "timestamp");
 
 ALTER TABLE public.messages2 OWNER TO datanommer;
 ALTER TABLE public.messages2_id_seq OWNER TO datanommer;