diff --git a/vendor/registripe/registripe/models.py b/vendor/registripe/registripe/models.py
index 6adb65a62edd52e8f74398cf9168eac6f8a4cac6..530109c2dca4110df475f437b99838f30ee8c676 100644
--- a/vendor/registripe/registripe/models.py
+++ b/vendor/registripe/registripe/models.py
@@ -7,8 +7,8 @@ from pinax.stripe.models import Charge
 
 class StripePayment(commerce.PaymentBase):
 
-    charge = models.ForeignKey(Charge)
+    charge = models.ForeignKey(Charge, on_delete=models.CASCADE)
 
 class StripeCreditNoteRefund(commerce.CreditNoteRefund):
 
-    charge = models.ForeignKey(Charge)
+    charge = models.ForeignKey(Charge, on_delete=models.CASCADE)