diff --git a/database/migrations/2025_04_08_083322_create_invoice_validations_table.php b/database/migrations/2025_04_08_083322_create_invoice_validations_table.php
index 489132b69..4cfcbda36 100644
--- a/database/migrations/2025_04_08_083322_create_invoice_validations_table.php
+++ b/database/migrations/2025_04_08_083322_create_invoice_validations_table.php
@@ -19,7 +19,7 @@ return new class extends Migration
             plant_id				        BIGINT NOT NULL,
 
             invoice_number                  TEXT NOT NULL,
-            serial_number		            TEXT UNIQUE,
+            serial_number		            TEXT DEFAULT NULL,
 
             motor_scanned_status            TEXT DEFAULT NULL,
             pump_scanned_status             TEXT DEFAULT NULL,
@@ -42,6 +42,7 @@ return new class extends Migration
             updated_at      				TIMESTAMP NOT NULL DEFAULT NOW(),
             deleted_at      				TIMESTAMP,
 
+            UNIQUE (plant_id, serial_number),
             FOREIGN KEY (sticker_master_id)  REFERENCES  sticker_masters (id),
             FOREIGN KEY (plant_id)           REFERENCES  plants (id)
         );