diff --git a/payments/models.py b/payments/models.py
index 2cbd8206a..c1c88a35e 100644
--- a/payments/models.py
+++ b/payments/models.py
@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 import json
 from uuid import uuid4
+from decimal import Decimal
 
 from django.conf import settings
 from django.core.urlresolvers import reverse
@@ -54,10 +55,10 @@ class BasePayment(models.Model):
     #: Currency code (may be provider-specific)
     currency = models.CharField(max_length=10)
     #: Total amount (gross)
-    total = models.DecimalField(max_digits=9, decimal_places=2, default='0.0')
-    delivery = models.DecimalField(
-        max_digits=9, decimal_places=2, default='0.0')
-    tax = models.DecimalField(max_digits=9, decimal_places=2, default='0.0')
+    total = models.DecimalField(max_digits=20, decimal_places=8, default=Decimal('0.0'))
+    delivery = models.DecimalField(max_digits=20,
+        decimal_places=8, default=Decimal('0.0'))
+    tax = models.DecimalField(max_digits=20, decimal_places=8, default=Decimal('0.0'))
     description = models.TextField(blank=True, default='')
     billing_first_name = models.CharField(max_length=256, blank=True)
     billing_last_name = models.CharField(max_length=256, blank=True)
@@ -73,7 +74,7 @@ class BasePayment(models.Model):
     message = models.TextField(blank=True, default='')
     token = models.CharField(max_length=36, blank=True, default='')
     captured_amount = models.DecimalField(
-        max_digits=9, decimal_places=2, default='0.0')
+        max_digits=20, decimal_places=8, default=Decimal('0.0'))
 
     class Meta:
         abstract = True