diff --git a/crypto.js b/crypto.js
index 959ccb3..1e0f0e0 100644
--- a/crypto.js
+++ b/crypto.js
@@ -73,7 +73,7 @@ function hexToBuf(hex) {
 
 function stripSDP(sdp) {
   return sdp.split(/\r?\n/).map(line => {
-    if (line === '' || line.startsWith('a=max-message-size:')) return null;
+    if (line === '' || line.startsWith('a=max-message-size:') || line.startsWith('a=sctp-port:')) return null;
     if (!line.startsWith('a=candidate:')) return line;
     const parts = line.split(' ');
     if (parts[2] === 'tcp') return null;