diff --git a/Distribution/Features/Returns/ReturnService.cs b/Distribution/Features/Returns/ReturnService.cs
index 731bc18..f747542 100644
--- a/Distribution/Features/Returns/ReturnService.cs
+++ b/Distribution/Features/Returns/ReturnService.cs
@@ -78,7 +78,9 @@ public class ReturnService(
         if (request.Items is null || request.Items.Count == 0)
             throw new InvalidOperationException("A return must have at least one line item.");
 
-        var sale = await saleRepo.GetByIdAsync(order.FK_SaleId)
+        if (order.FK_SaleId is null)
+            throw new InvalidOperationException("Sale not found for this order.");
+        var sale = await saleRepo.GetByIdAsync(order.FK_SaleId.Value)
             ?? throw new InvalidOperationException("Sale not found for this order.");
         if (sale.FK_RideId is null)
             throw new InvalidOperationException("A return can only be recorded for an order created during an active ride.");