diff --git a/src/authentic2_cut/apps.py b/src/authentic2_cut/apps.py
index 20b3ee5..82d55d3 100644
--- a/src/authentic2_cut/apps.py
+++ b/src/authentic2_cut/apps.py
@@ -292,7 +292,9 @@ class AppConfig(django.apps.AppConfig):
 
         if view.__class__.__name__ == 'UsersAPI':
             del serializer.fields['id']
-            serializer.fields['sub'] = serializer.fields['uuid']
+            # use deepcopy to prevent overwrite of field.field_name
+            # see: https://github.com/encode/django-rest-framework/blob/bce9df9b5e0f54a6076519835393fea59accb40c/rest_framework/utils/serializer_helpers.py#L169
+            serializer.fields['sub'] = copy.deepcopy(serializer.fields['uuid'])
             del serializer.fields['is_superuser']
             del serializer.fields['is_staff']
             del serializer.fields['password']