diff --git a/tcpip.cpp b/tcpip.cpp
index ef326cd..4ab40af 100755
--- a/tcpip.cpp
+++ b/tcpip.cpp
@@ -314,7 +314,8 @@ byte EtherCard::ntpProcessAnswer (uint32_t *time,byte dstport_l) {
 void EtherCard::udpPrepare (word sport, byte *dip, word dport) {
   setMACandIPs(gwmacaddr, dip);
   // see http://tldp.org/HOWTO/Multicast-HOWTO-2.html
-  if ((dip[0] & 0xF0) == 0xE0) // multicast address
+  // multicast or broadcast address, https://github.com/jcw/ethercard/issues/59
+  if ((dip[0] & 0xF0) == 0xE0 || *((long*) dip) == 0xFFFFFFFF)
     EtherCard::copyMac(gPB + ETH_DST_MAC, allOnes);
   gPB[ETH_TYPE_H_P] = ETHTYPE_IP_H_V;
   gPB[ETH_TYPE_L_P] = ETHTYPE_IP_L_V;