diff --git a/django_messages/fields.py b/django_messages/fields.py
index d1ac75c..37024a2 100644
--- a/django_messages/fields.py
+++ b/django_messages/fields.py
@@ -15,7 +15,7 @@
 class CommaSeparatedUserInput(widgets.Input):
     input_type = 'text'
 
-    def render(self, name, value, **kwargs):
+    def render(self, name, value, **kwargs, renderer = None):
         if value is None:
             value = ''
         elif isinstance(value, (list, tuple)):