diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@
 attrs-strict
 celery >= 4.3
 # Not a direct dependency: missing from celery 4.4.4
-future >= 0.18.0
+future >= 0.16.0
 Click
 elasticsearch > 5.4
 flask