diff --git a/systemd/conservancy-www-update.service b/systemd/conservancy-www-update.service
index 5ccaca8498457d48098c65438e7c4a6744f6ef4a..e1d5b1821157f8db412f9710665f0d58961aa595 100644
--- a/systemd/conservancy-www-update.service
+++ b/systemd/conservancy-www-update.service
@@ -1,3 +1,5 @@
+# Run the website update script (see also: conservancy-www-update.timer).
+
 [Unit]
 Description=Update Conservancy website checkout