diff --git a/lib/middleware.js b/lib/middleware.js
index 39e5a4cc..eb006971 100644
--- a/lib/middleware.js
+++ b/lib/middleware.js
@@ -97,7 +97,7 @@ module.exports = function(srf, logger) {
     if (req.has('X-MS-Teams-Tenant-FQDN')) req.locals.msTeamsTenant = req.get('X-MS-Teams-Tenant-FQDN');
     if (req.has('X-Cisco-Recording-Participant')) {
       const ciscoParticipants = req.get('X-Cisco-Recording-Participant');
-      const regex = /sip:[\d]+@[\d]+\.[\d]+\.[\d]+\.[\d]+/g;
+      const regex = /sip:[a-zA-Z0-9]+@[a-zA-Z0-9.-_]+/g;
       const sipURIs = ciscoParticipants.match(regex);
       logger.info(`X-Cisco-Recording-Participant : ${sipURIs} `);
       if (sipURIs && sipURIs.length > 0) {