diff --git a/crypto.js b/crypto.js
index e043782..959ccb3 100644
--- a/crypto.js
+++ b/crypto.js
@@ -72,7 +72,8 @@ function hexToBuf(hex) {
 /* ─── QR compression: deflate-raw + base45 ─── */
 
 function stripSDP(sdp) {
-  return sdp.split('\r\n').map(line => {
+  return sdp.split(/\r?\n/).map(line => {
+    if (line === '' || line.startsWith('a=max-message-size:')) return null;
     if (!line.startsWith('a=candidate:')) return line;
     const parts = line.split(' ');
     if (parts[2] === 'tcp') return null;