diff --git a/server/AyaNova/util/AySchema.cs b/server/AyaNova/util/AySchema.cs
index 087d8668..63a13530 100644
--- a/server/AyaNova/util/AySchema.cs
+++ b/server/AyaNova/util/AySchema.cs
@@ -721,11 +721,11 @@ $BODY$ LANGUAGE PLPGSQL STABLE");
                 "unitmodelid bigint null references aunitmodel(id), unithasownaddress bool, boughthere bool, purchasedfromvendorid bigint null references avendor(id), " +
                 "receipt text null, purchaseddate timestamp null, description text null, replacedbyunitid bigint null references aunit(id), " +
                 "overridemodelwarranty bool, warrantylength integer null, warrantyterms text null, usesbanking bool, metered bool, lifetimewarranty bool, " +
-                "text1 text null, text2 text null, text3 text null, text4 text null " +
-                " )");
+                "text1 text null, text2 text null, text3 text null, text4 text null, " +
+                "CONSTRAINT UNQ_UnitSerialModelId UNIQUE (serial, unitmodelid) " +
+                " )");               
                
-               
-               // await ExecQueryAsync("CREATE UNIQUE INDEX aunit_name_id_idx ON aunit (id, name);");
+                await ExecQueryAsync("CREATE UNIQUE INDEX aunit_serial_id_idx ON aunit (id, serial);");
                 await ExecQueryAsync("CREATE INDEX aunit_tags ON aunit using GIN(tags)");