chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
        chunksize += sizeof(ecap_param);
 
+       if (sctp_prsctp_enable)
+               chunksize += sizeof(prsctp_param);
+
        /* ADDIP: Section 4.2.7:
         *  An implementation supporting this extension [ADDIP] MUST list
         *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
        if (asoc->peer.ecn_capable)
                chunksize += sizeof(ecap_param);
 
+       if (sctp_prsctp_enable)
+               chunksize += sizeof(prsctp_param);
+
        if (sctp_addip_enable) {
                extensions[num_ext] = SCTP_CID_ASCONF;
                extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;