diff --git a/api/utils/serializer/v1/serializer.py b/api/utils/serializer/v1/serializer.py
index 984038da..63c71827 100644
--- a/api/utils/serializer/v1/serializer.py
+++ b/api/utils/serializer/v1/serializer.py
@@ -63,6 +63,8 @@ class AbstractModelAPISerializerV1(AbstractModelAPISerializer):
         Returns:
 
         """
+        if json_str is None or len(json_str) == 0:
+            return None
         code = KonovaCode.objects.get(
             atom_id=json_str,
             code_lists__in=[code_list_identifier]