diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
 
 arrow
-celery
+celery<4
 Click
 psycopg2
 vcversioner