diff --git a/billing/invoice/service.go b/billing/invoice/service.go
index 15b4fb896..d7b0d0578 100644
--- a/billing/invoice/service.go
+++ b/billing/invoice/service.go
@@ -363,6 +363,10 @@ func (s *Service) upsert(ctx context.Context, customerID string,
 			existingInvoice.HostedURL = stripeInvoice.HostedInvoiceURL
 			updateNeeded = true
 		}
+		if existingInvoice.Amount != stripeInvoice.Total {
+			existingInvoice.Amount = stripeInvoice.Total
+			updateNeeded = true
+		}
 
 		if updateNeeded {
 			if _, err := s.repository.UpdateByID(ctx, *existingInvoice); err != nil {
diff --git a/internal/store/postgres/billing_invoice_repository.go b/internal/store/postgres/billing_invoice_repository.go
index c1d36d791..f80d4f383 100644
--- a/internal/store/postgres/billing_invoice_repository.go
+++ b/internal/store/postgres/billing_invoice_repository.go
@@ -297,6 +297,9 @@ func (r BillingInvoiceRepository) UpdateByID(ctx context.Context, toUpdate invoi
 	if toUpdate.HostedURL != "" {
 		updateRecord["hosted_url"] = toUpdate.HostedURL
 	}
+	// Do not guard this with `!= 0` like the fields above: an invoice can
+	// be credited down to zero, and that zero must be saved.
+	updateRecord["amount"] = toUpdate.Amount
 
 	query, params, err := dialect.Update(TABLE_BILLING_INVOICES).Set(updateRecord).Where(goqu.Ex{
 		"id": toUpdate.ID,