diff --git a/roles/calibre-web/templates/calibre-web.conf.j2 b/roles/calibre-web/templates/calibre-web.conf.j2
index 052cc66ce..a4fb4ee37 100644
--- a/roles/calibre-web/templates/calibre-web.conf.j2
+++ b/roles/calibre-web/templates/calibre-web.conf.j2
@@ -11,7 +11,9 @@ RequestHeader set X-SCHEME http
 
 ProxyPass {{ calibreweb_url }} http://localhost:{{ calibreweb_port }}/
 
-# Appears unnec:
+# Possibly unnec?  (ProxyPassReverse rewrites internal links, that come back
+# from proxy!  Whereas e.g. kiwix.conf doesn't need this, as kiwix itself
+# prefixes URLs, thanks to --urlRootLocation=/kiwix/ in its systemd file.)
 ProxyPassReverse {{ calibreweb_url }} http://localhost:{{ calibreweb_port }}/
 
 #    </Location>