diff --git a/html/includes/print-graph-alerts.inc.php b/html/includes/print-graph-alerts.inc.php
index 6479d7a7dc..de6f31600e 100644
--- a/html/includes/print-graph-alerts.inc.php
+++ b/html/includes/print-graph-alerts.inc.php
@@ -11,6 +11,7 @@
 */
 $pagetitle[] = "Alert Stats";
 
+$sql = "";
 if (isset($device['device_id']) && $device['device_id'] > 0) {
     $sql = " AND alert_log.device_id=?";
     $param = array(