diff --git a/rest_framework_serializer_field_permissions/permissions.py b/rest_framework_serializer_field_permissions/permissions.py
index <HASH>..<HASH> 100644
--- a/rest_framework_serializer_field_permissions/permissions.py
+++ b/rest_framework_serializer_field_permissions/permissions.py
@@ -50,4 +50,4 @@ class IsAuthenticated(BaseFieldPermission):
     """
 
     def has_permission(self, request):
-        return request.user and request.user.is_authenticated()
+        return request.user and request.user.is_authenticated
Adapt to Django <I>+  interface.