diff --git a/CHANGELOG b/CHANGELOG
index 49694f370..6bf440899 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [GH#283][Nsock] Avoid "unknown protocol:0" debug messages and an "Unknown
+  address family 0" crash on Windows and other platforms that do not set the
+  src_addr argument to recvfrom for TCP sockets. [Daniel Miller]
+
 o [NSE][GH#371] Fix mysql-audit by adding needed library requires to the
   mysql-cis.audit file. The script would fail with "Failed to load rulebase"
   message. [Paolo Perego]
diff --git a/nsock/src/nsock_core.c b/nsock/src/nsock_core.c
index 0167c974e..47293144b 100644
--- a/nsock/src/nsock_core.c
+++ b/nsock/src/nsock_core.c
@@ -644,7 +644,11 @@ static int do_actual_read(struct npool *ms, struct nevent *nse) {
         err = socket_errno();
         break;
       }
-      if (peerlen > 0) {
+      /* Windows will ignore src_addr and addrlen arguments to recvfrom on TCP
+       * sockets, so peerlen is still sizeof(peer) and peer is junk. Instead,
+       * only set this if it's not already set.
+       */
+      if (peerlen > 0 && iod->peerlen == 0) {
         assert(peerlen <= sizeof(iod->peer));
         memcpy(&iod->peer, &peer, peerlen);
         iod->peerlen = peerlen;