From f4c48cc1fd642e20e1aaf163fcc74892a7be331a Mon Sep 17 00:00:00 2001
From: Sebastian Chamena <sebastian.chamena@talkiu.com>
Date: Mon, 27 May 2019 22:06:45 -0300
Subject: [PATCH] fixes ListField bug

---
 graphene_mongo/types.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/graphene_mongo/types.py b/graphene_mongo/types.py
index 84771248..b769913f 100644
--- a/graphene_mongo/types.py
+++ b/graphene_mongo/types.py
@@ -35,7 +35,9 @@ def construct_fields(model, registry, only_fields, exclude_fields):
             # in there. Or when we exclude this field in exclude_fields
             continue
         if isinstance(field, mongoengine.ListField):
-            # Take care of list of self-reference.
+            if not field.field:
+                continue
+             # Take care of list of self-reference.
             document_type_obj = field.field.__dict__.get('document_type_obj', None)
             if document_type_obj == model._class_name \
                     or isinstance(document_type_obj, model) \