diff --git a/tests/app/main/views/test_jobs.py b/tests/app/main/views/test_jobs.py
index c82ead594..f6e9b0ea4 100644
--- a/tests/app/main/views/test_jobs.py
+++ b/tests/app/main/views/test_jobs.py
@@ -349,6 +349,12 @@ def test_should_show_job_without_notifications(
         'No messages to show yet…'
     )),
     # Created a while ago, started exactly 24h ago
+    # ---
+    # It doesn’t matter that 24h (1 day) and 7 days (the service’s data
+    # retention) don’t match up. We’re testing the case of no
+    # notifications existing more than 1 day after the job started
+    # processing. In this case we assume it’s because the service’s
+    # data retention has kicked in.
     (datetime(2020, 1, 1, 0, 0, 0), datetime(2020, 1, 9, 1, 0, 0), (
         'These messages have been deleted because they were sent more than 7 days ago'
     )),