diff --git a/src/serverlib/calendar.class.php b/src/serverlib/calendar.class.php
index ec20fd6..00d9d1b 100644
--- a/src/serverlib/calendar.class.php
+++ b/src/serverlib/calendar.class.php
@@ -374,7 +374,7 @@ class BMCalendar
      *
      * @return bool
      */
-    public function _sendNotification($date)
+    private static function _sendNotification($date)
     {
         global $db, $bm_prefs;