diff --git a/registrasion/controllers/invoice.py b/registrasion/controllers/invoice.py
index 62bab0b626d08e71e2068b8f4ec67ec40f38a8d0..9ef155efa356cb50f40240617adaee6632de4e89 100644
--- a/registrasion/controllers/invoice.py
+++ b/registrasion/controllers/invoice.py
@@ -29,6 +29,7 @@ class InvoiceController(ForId, object):
         If such an invoice does not exist, the cart is validated, and if valid,
         an invoice is generated.'''
 
+        cart.refresh_from_db()
         try:
             invoice = commerce.Invoice.objects.exclude(
                 status=commerce.Invoice.STATUS_VOID,
@@ -74,6 +75,8 @@ class InvoiceController(ForId, object):
     def _generate(cls, cart):
         ''' Generates an invoice for the given cart. '''
 
+        cart.refresh_from_db()
+
         issued = timezone.now()
         reservation_limit = cart.reservation_duration + cart.time_last_updated
         # Never generate a due time that is before the issue time
@@ -251,6 +254,9 @@ class InvoiceController(ForId, object):
     def _invoice_matches_cart(self):
         ''' Returns true if there is no cart, or if the revision of this
         invoice matches the current revision of the cart. '''
+
+        self._refresh()
+
         cart = self.invoice.cart
         if not cart:
             return True