diff --git a/django_roa/db/query.py b/django_roa/db/query.py
index 28cba55..985444a 100644
--- a/django_roa/db/query.py
+++ b/django_roa/db/query.py
@@ -234,12 +234,13 @@ def iterator(self):
             result = []
 
             serializer = self.model.get_serializer(data=data)
-            for field in serializer.child.fields.items():
-                validators = field[1].validators
-                field[1].validators = []
-                for validator in validators:
-                    if validator.__class__.__name__ != "UniqueValidator":
-                        field[1].validators.append(validator)
+            if hasattr(serializer, 'child'):
+                for field in serializer.child.fields.items():
+                    validators = field[1].validators
+                    field[1].validators = []
+                    for validator in validators:
+                        if validator.__class__.__name__ != "UniqueValidator":
+                            field[1].validators.append(validator)
 
             if not serializer.is_valid():
                 raise ROAException('Invalid deserialization for %s model: %s' % (self.model, serializer.errors))