diff --git a/calendar/inc/class.socal.inc.php b/calendar/inc/class.socal.inc.php
index 1b1b88b30a..8956ef4f6b 100644
--- a/calendar/inc/class.socal.inc.php
+++ b/calendar/inc/class.socal.inc.php
@@ -515,7 +515,7 @@ ORDER BY cal_user_type, cal_usre_id
 				return false;
 			}
 			// new event (without uid), not strong enough uid or new created referencing event => create new uid
-			if (strlen($event['cal_uid']) < 20 || is_nummeric($event['cal_uid']) ||
+			if (strlen($event['cal_uid']) < 20 || is_numeric($event['cal_uid']) ||
 				$event['cal_reference'] && strpos($event['cal_uid'],'cal-'.$event['calreference'].'-') !== false)
 			{
 				$event['cal_uid'] = $GLOBALS['egw']->common->generate_uid('calendar',$cal_id);