diff --git a/mod/admin.php b/mod/admin.php
index 6333cb5321..8d2a7688f8 100644
--- a/mod/admin.php
+++ b/mod/admin.php
@@ -774,7 +774,7 @@ function admin_page_site(&$a) {
 		'$poll_interval'	=> array('poll_interval', t("Poll interval"), (x(get_config('system','poll_interval'))?get_config('system','poll_interval'):2), t("Delay background polling processes by this many seconds to reduce system load. If 0, use delivery interval.")),
 		'$maxloadavg'		=> array('maxloadavg', t("Maximum Load Average"), ((intval(get_config('system','maxloadavg')) > 0)?get_config('system','maxloadavg'):50), t("Maximum system load before delivery and poll processes are deferred - default 50.")),
 		'$maxloadavg_frontend'	=> array('maxloadavg_frontend', t("Maximum Load Average (Frontend)"), ((intval(get_config('system','maxloadavg_frontend')) > 0)?get_config('system','maxloadavg_frontend'):50), t("Maximum system load before the frontend quits service - default 50.")),
-		'$optimize_max_tablesize'=> array('optimize_max_tablesize', t("Maximum table size for optimisation"), ((intval(get_config('system','optimize_max_tablesize')) > 0)?get_config('system','optimize_max_tablesize'):100), t("Maximum table size (in MB) for the automatic optimization - default 100 MB.")),
+		'$optimize_max_tablesize'=> array('optimize_max_tablesize', t("Maximum table size for optimization"), ((intval(get_config('system','optimize_max_tablesize')) > 0)?get_config('system','optimize_max_tablesize'):100), t("Maximum table size (in MB) for the automatic optimization - default 100 MB. Enter -1 to disable it.")),
 
 		'$poco_completion'	=> array('poco_completion', t("Periodical check of global contacts"), get_config('system','poco_completion'), t("If enabled, the global contacts are checked periodically for missing or outdated data and the vitality of the contacts and servers.")),
 		'$poco_requery_days'	=> array('poco_requery_days', t("Days between requery"), get_config('system','poco_requery_days'), t("Number of days after which a server is requeried for his contacts.")),