diff --git a/mayan/apps/documents/tasks.py b/mayan/apps/documents/tasks.py
index 09c5cef3fc..53efd9975e 100644
--- a/mayan/apps/documents/tasks.py
+++ b/mayan/apps/documents/tasks.py
@@ -6,6 +6,7 @@ from django.apps import apps
 from django.contrib.auth import get_user_model
 from django.db import OperationalError
 
+from converter.transformations import BaseTransformation
 from mayan.celery import app
 
 from .literals import (