diff --git a/SVSim.EmulatedEntrypoint/Controllers/ItemPurchaseController.cs b/SVSim.EmulatedEntrypoint/Controllers/ItemPurchaseController.cs
index 5d2fe59..f39a5fc 100644
--- a/SVSim.EmulatedEntrypoint/Controllers/ItemPurchaseController.cs
+++ b/SVSim.EmulatedEntrypoint/Controllers/ItemPurchaseController.cs
@@ -114,7 +114,7 @@ public class ItemPurchaseController : SVSimController
         if (rest <= 0)
             return BadRequest(new { error = "sold_out" });
 
-        await using var tx = await _inv.BeginAsync(viewerId, HttpContext.RequestAborted);
+        await using var tx = await _inv.BeginAsync(viewerId, HttpContext.RequestAborted, cfg => cfg.Source = GrantSource.ItemPurchase);
 
         // Debit the require side via the tx.
         var debit = await tx.TryDebitAsync(