diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/opac.pref b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/opac.pref
index 2e43a328b6..58751f119b 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/opac.pref
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/opac.pref
@@ -809,6 +809,7 @@ OPAC:
             - pref: PatronSelfRegistrationDefaultCategory
               class: short
             - "as the default patron category for patrons registered via the OPAC."
+            - "<br><strong>WARNING: Do not use a regular patron category for self registration.</strong> If the <code>misc/cronjobs/cleanup_database.pl</code> cronjob is setup to delete unverified and unfinished OPAC self registrations, it will permanently and unrecoverably delete all patrons that have registered more than PatronSelfRegistrationExpireTemporaryAccountsDelay days ago."
         -
             - "Delete patrons still in the category indicated by PatronSelfRegistrationDefaultCategory"
             - pref: PatronSelfRegistrationExpireTemporaryAccountsDelay