diff --git a/debian/control b/debian/control
--- a/debian/control
+++ b/debian/control
@@ -6,7 +6,7 @@
                dh-python (>= 2),
                python3-all,
                python3-arrow,
-               python3-celery,
+               python3-celery (>= 4),
                python3-click,
                python3-elasticsearch (>= 5.4.0),
                python3-flask,
diff --git a/requirements-test.txt b/requirements-test.txt
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,3 +1,3 @@
 hypothesis
 pytest
-celery
+celery >= 4
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
 elasticsearch > 5.4
 flask