diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,9 @@
 attrs
 attrs-strict
 celery >= 4.3, != 5.0.3
+
+importlib_metadata<5.0  # workaround against new kombu release using a most recent
+                        # version (with breaking compatibility)
 click
 flask
 humanize