diff --git a/webstack_django_sorting/templatetags/sorting_tags.py b/webstack_django_sorting/templatetags/sorting_tags.py
index 5dc4a9f..6c5f77e 100644
--- a/webstack_django_sorting/templatetags/sorting_tags.py
+++ b/webstack_django_sorting/templatetags/sorting_tags.py
@@ -112,12 +112,12 @@ def render(self, context):
 
         queryset = self.queryset_var.resolve(context)
         order_by = common.get_order_by_from_request(context["request"])
-        self.null_ordering = common.get_null_ordering(
+        null_ordering = common.get_null_ordering(
             context["request"], self.null_ordering
         )
 
         try:
-            context[key] = common.sort_queryset(queryset, order_by, self.null_ordering)
+            context[key] = common.sort_queryset(queryset, order_by, null_ordering)
         except ValueError as e:
             raise template.TemplateSyntaxError from e
         except AttributeError: