diff --git a/lib/grammar.js b/lib/grammar.js
index <HASH>..<HASH> 100644
--- a/lib/grammar.js
+++ b/lib/grammar.js
@@ -339,14 +339,14 @@ var grammar = module.exports = {
       // RFC version 26 for SCTP over DTLS
       // https://tools.ietf.org/html/draft-ietf-mmusic-sctp-sdp-26#section-5
       name:'sctpPort',
-      reg: /^sctp-port:([0-9]{1,4}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])$/,
+      reg: /^sctp-port:(\d+)$/,
       format: 'sctp-port:%s'
     },
     {
       // RFC version 26 for SCTP over DTLS
       // https://tools.ietf.org/html/draft-ietf-mmusic-sctp-sdp-26#section-6
       name:'maxMessageSize',
-      reg: /^max-message-size:(0|([1-9][0-9]*))$/,
+      reg: /^max-message-size:(\d+)$/,
       format: 'max-message-size:%s'
     },
     { // any a= that we don't understand is kepts verbatim on media.invalid
simplify regex to match just digits