diff --git a/lib/call-session.js b/lib/call-session.js
index 2bd859e..2403da0 100644
--- a/lib/call-session.js
+++ b/lib/call-session.js
@@ -861,15 +861,17 @@ Duration=${payload.duration} `
         }
       }
       else {
-        const response = await dlg.other.request({
-          method: 'INFO',
-          headers: req.headers,
-          body: req.body
-        });
-        res.send(response.status, {
-          headers: response.headers,
-          body: response.body
+        const immutableHdrs = ['via', 'from', 'to', 'call-id', 'cseq', 'max-forwards', 'content-length'];
+        const headers = {};
+        Object.keys(req.headers).forEach((h) => {
+          if (!immutableHdrs.includes(h)) headers[h] = req.headers[h];
         });
+        const response = await dlg.other.request({method: 'INFO', headers, body: req.body});
+        const responseHeaders = {};
+        if (response.has('Content-Type')) {
+          Object.assign(responseHeaders, {'Content-Type': response.get('Content-Type')});
+        }
+        res.send(response.status, {headers: responseHeaders, body: response.body});
       }
     } catch (err) {
       this.logger.info({err}, `Error handing INFO request on ${dlg.type} leg`);