diff --git a/pkg/checkout/mutation_payment_completed.go b/pkg/checkout/mutation_payment_completed.go
index 2e01d38..83207ef 100644
--- a/pkg/checkout/mutation_payment_completed.go
+++ b/pkg/checkout/mutation_payment_completed.go
@@ -29,9 +29,9 @@ func HandlePaymentCompleted(g *CheckoutGrain, m *messages.PaymentCompleted) erro
 	}
 
 	if m.CompletedAt != nil {
-		*payment.CompletedAt = m.CompletedAt.AsTime()
+		payment.CompletedAt = asPointer(m.CompletedAt.AsTime())
 	} else {
-		*payment.CompletedAt = time.Now()
+		payment.CompletedAt = asPointer(time.Now())
 	}
 
 	// Update checkout status