diff --git a/ox/django/fields.py b/ox/django/fields.py
index e40240e..8ab6862 100644
--- a/ox/django/fields.py
+++ b/ox/django/fields.py
@@ -53,7 +53,7 @@ class DictField(models.TextField):
         """Convert our JSON object to a string before we save"""
         assert isinstance(value, dict)
         value = json.dumps(value, default=to_json)
-        return super(DictField, self).get_db_prep_save(value, connection)
+        return super(DictField, self).get_db_prep_save(value, connection=connection)
 
 class TupleField(models.TextField):
     """TupleField is a textfield that contains JSON-serialized tuples."""
@@ -77,7 +77,7 @@ class TupleField(models.TextField):
         """Convert our JSON object to a string before we save"""
         assert isinstance(value, tuple)
         value = json.dumps(value, default=to_json)
-        return super(TupleField, self).get_db_prep_save(value, connection)
+        return super(TupleField, self).get_db_prep_save(value, connection=connection)
 
 try:
     from south.modelsinspector import add_introspection_rules