diff --git a/lib/call-session.js b/lib/call-session.js
index 865a1ad..86281d6 100644
--- a/lib/call-session.js
+++ b/lib/call-session.js
@@ -40,11 +40,13 @@ const initCdr = (srf, req) => {
   const to = arr ? arr[1] : req.calledNumber;
   arr = regex.exec(req.callingNumber);
   const from = arr ? arr[1] : req.callingNumber;
+  const applicationSid = req.get('X-Application-Sid');
 
   return {
     account_sid: req.get('X-Account-Sid'),
     call_sid: req.get('X-Call-Sid'),
     sip_callid: req.get('Call-ID'),
+    ...(applicationSid && {application_sid: applicationSid}),
     from,
     to,
     duration: 0,