diff --git a/apps/edr-freight-web/portal/src/pages/contracts/NewShipmentPage.tsx b/apps/edr-freight-web/portal/src/pages/contracts/NewShipmentPage.tsx
index 80fcabc8b..63070003a 100644
--- a/apps/edr-freight-web/portal/src/pages/contracts/NewShipmentPage.tsx
+++ b/apps/edr-freight-web/portal/src/pages/contracts/NewShipmentPage.tsx
@@ -311,7 +311,7 @@ function mapBookingToShipmentValues(
     const sizes = (contract.cargoScope ?? [])
       .map((s) => s.containerSize)
       .filter((s): s is "20ft" | "40ft" => s === "20ft" || s === "40ft");
-    values.containers = (sizes.length ? sizes : ["20ft", "40ft"]).map(lineFor);
+    values.containers = (sizes.length ? sizes : (["20ft", "40ft"] as const)).map(lineFor);
   } else {
     const perItem = bulkUnitOfMeasure(contract) === "PER_ITEM";
     const amount = Number(b.cargoTotalWeightVgm ?? 0);