diff --git a/app/xml_cdr/xml_cdr_details.php b/app/xml_cdr/xml_cdr_details.php
index b4a2512de2..87d5eff97c 100644
--- a/app/xml_cdr/xml_cdr_details.php
+++ b/app/xml_cdr/xml_cdr_details.php
@@ -248,7 +248,7 @@
echo " | ".escape($destination_number)." | \n";
echo " ".escape($start_stamp)." | \n";
echo " ".escape($end_stamp)." | \n";
- echo " ".escape(gmdate("G:i:s", $duration))." | \n";
+ echo " ".escape(gmdate("G:i:s", $duration ?? 0))." | \n";
echo " ".escape($hangup_cause)." | \n";
echo "";
echo "
\n";