diff --git a/src/c3nav/mapdata/utils/models.py b/src/c3nav/mapdata/utils/models.py
index 5f6bbd88..96c951dd 100644
--- a/src/c3nav/mapdata/utils/models.py
+++ b/src/c3nav/mapdata/utils/models.py
@@ -1,6 +1,6 @@
 import typing
+from itertools import chain
 
-from celery import chain
 from django.db import models
 
 _submodels_by_model = {}