diff --git a/CHANGES b/CHANGES
index 5afbc74..fdc6b04 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,10 @@
 
+Corrections:
+	With version 1.8.0.0, the following command failed:
+	socat UDP-LISTEN:1234,fork,reuseaddr,bind=127.0.0.1 -
+	Message: "E xioopen_ipdgram_listen(): unknown address family 0":
+	Thanks to Brian Woo for reporting this issue.
+
 ####################### V 1.8.0.0
 
 Security:
diff --git a/test.sh b/test.sh
index f70ad89..1d5298b 100755
--- a/test.sh
+++ b/test.sh
@@ -2977,19 +2977,21 @@ echo "$da" |$CMD2 >>"$tf" 2>>"${te}2"
 rc2=$?
 kill $pid1 2>/dev/null; wait
 if [ $rc2 -ne 0 ]; then
-   $PRINTF "$FAILED: $TRACE $SOCAT:\n"
+   $PRINTF "$FAILED (rc2=$rc2)\n"
    echo "$CMD1 &"
+   cat "${te}1" >&2
    echo "$CMD2"
-   cat "${te}1" "${te}2"
+   cat "${te}2" >&2
    numFAIL=$((numFAIL+1))
    listFAIL="$listFAIL $N"
 elif ! echo "$da" |diff - "$tf" >"$tdiff"; then
-   $PRINTF "$FAILED\n"
+   $PRINTF "$FAILED (diff)\n"
    echo "$CMD1 &"
-   cat "${te}1"
+   cat "${te}1" >&2
    echo "$CMD2"
-   cat "${te}2"
-   cat "$tdiff"
+   cat "${te}2" >&2
+   echo "// diff:" >&2
+   cat "$tdiff" >&2
    numFAIL=$((numFAIL+1))
    listFAIL="$listFAIL $N"
 else
@@ -3028,15 +3030,21 @@ echo "$da" |$CMD2 >>"$tf" 2>>"${te}2"
 rc2=$?
 kill $pid1 2>/dev/null; wait
 if [ $rc2 -ne 0 ]; then
-   $PRINTF "$FAILED: $TRACE $SOCAT:\n"
+   $PRINTF "$FAILED (rc2=$rc2)\n"
    echo "$CMD1 &"
+   cat "${te}1" >&2
    echo "$CMD2"
-   cat "${te}1" "${te}2"
+   cat "${te}2" >&2
    numFAIL=$((numFAIL+1))
    listFAIL="$listFAIL $N"
 elif ! echo "$da" |diff - "$tf" >"$tdiff"; then
-   $PRINTF "$FAILED\n"
-   cat "$tdiff"
+   $PRINTF "$FAILED (diff)\n"
+   echo "$CMD1 &"
+   cat "${te}1" >&2
+   echo "$CMD2"
+   cat "${te}2" >&2
+   echo "// diff:" >&2
+   cat "$tdiff" >&2
    numFAIL=$((numFAIL+1))
    listFAIL="$listFAIL $N"
 else
@@ -19154,6 +19162,76 @@ esac
 N=$((N+1))
 
 
+# Test UDP-LISTEN with bind to IPv4 address; this failed with Socat version
+# 1.8.0.0
+NAME=UDP_LISTEN_BIND4
+case "$TESTS" in
+*%$N%*|*%functions%*|*%bugs%*|*%socket%*|*%ip4%*|*%udp%*|*%udp4%*|*%listen%*|*%$NAME%*)
+TEST="$NAME: Test UDP-LISTEN with bind to IPv4 addr"
+# Start a listener with UDP-LISTEN and bind to 127.0.0.1; when it starts
+# without error and even processes data the test succeeded
+if ! eval $NUMCOND; then :
+# Remove unneeded checks, adapt lists of the remaining ones
+elif ! cond=$(checkconds \
+		  "" \
+		  "" \
+		  "" \
+		  "IP4 UDP LISTEN STDIO PIPE" \
+		  "UDP-LISTEN PIPE STDIO UDP" \
+		  "bind" \
+		  "udp4" ); then
+    $PRINTF "test $F_n $TEST... ${YELLOW}$cond${NORMAL}\n" $N
+    numCANT=$((numCANT+1))
+    listCANT="$listCANT $N"
+    namesCANT="$namesCANT $NAME"
+else
+    tf="$td/test$N.stdout"
+    te="$td/test$N.stderr"
+    tdiff="$td/test$N.diff"
+    da="test$N $(date) $RANDOM"
+    newport udp4
+    CMD0="$TRACE $SOCAT $opts UDP-LISTEN:$PORT,bind=$LOCALHOST4 PIPE"
+    CMD1="$TRACE $SOCAT $opts - UDP-CONNECT:$LOCALHOST4:$PORT"
+    printf "test $F_n $TEST... " $N
+    $CMD0 >/dev/null 2>"${te}0" &
+    pid0=$!
+    waitudp4port $PORT 1
+    echo "$da" |$CMD1 >"${tf}1" 2>"${te}1"
+    rc1=$?
+    kill $pid0 2>/dev/null; wait
+    if [ "$rc1" -ne 0 ]; then
+	$PRINTF "$FAILED (rc1=$rc1)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	echo "$CMD1"
+	cat "${te}1" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    elif ! echo "$da" |diff - "${tf}1" >$tdiff; then
+	$PRINTF "$FAILED (diff)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	echo "$CMD1"
+	cat "${te}1" >&2
+	echo "// diff:" >&2
+	cat "$tdiff" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    else
+	$PRINTF "$OK\n"
+	if [ "$VERBOSE" ]; then echo "$CMD0 &"; fi
+	if [ "$DEBUG" ];   then cat "${te}0" >&2; fi
+	if [ "$VERBOSE" ]; then echo "$CMD1"; fi
+	if [ "$DEBUG" ];   then cat "${te}1" >&2; fi
+	numOK=$((numOK+1))
+    fi
+fi # NUMCOND
+ ;;
+esac
+N=$((N+1))
+
 # end of common tests
 
 ##################################################################################
diff --git a/xio-socket.c b/xio-socket.c
index c869b6d..ed10a99 100644
--- a/xio-socket.c
+++ b/xio-socket.c
@@ -262,7 +262,7 @@ static int xioopen_socket_connect(
    sfd->dtype = XIOREAD_STREAM|XIOWRITE_STREAM;
 
    socket_init(0, &us);
-   if (retropt_bind(opts, 0 /*pf*/, socktype, proto, (struct sockaddr *)&us, &uslen, 3,
+   if (retropt_bind(opts, pf, socktype, proto, (struct sockaddr *)&us, &uslen, 0,
 		    sfd->para.socket.ip.ai_flags)
        != STAT_NOACTION) {
       needbind = true;
diff --git a/xio-udp.c b/xio-udp.c
index b624281..d511122 100644
--- a/xio-udp.c
+++ b/xio-udp.c
@@ -277,8 +277,10 @@ int xioopen_ipdgram_listen(
    int pf = addrdesc->arg1;
    int ipproto = addrdesc->arg2;
    union sockaddr_union us;
+   int bind_rc;
    int socktype = SOCK_DGRAM;
    socklen_t uslen;
+   int result;
 
    if (argc != 2) {
       xio_syntax(argv[0], 1, argc-1, addrdesc->syntax);
@@ -308,12 +310,31 @@ int xioopen_ipdgram_listen(
    applyopts(sfd, -1, opts, PH_INIT);
 
    uslen = socket_init(pf, &us);
-   retropt_bind(opts, pf, socktype, ipproto,
+   bind_rc = retropt_bind(opts, pf, socktype, ipproto,
 		(struct sockaddr *)&us, &uslen, 1,
 		xfd->stream.para.socket.ip.ai_flags);
+   if (bind_rc == STAT_NORETRY)
+      return STAT_NORETRY;
+   if (pf == PF_UNSPEC && bind_rc == STAT_OK)
+      pf = us.soa.sa_family;
 
    if (false) {
       ;
+#if WITH_IP4 || WITH_IP6
+   } else if (pf == PF_UNSPEC && bind_rc == STAT_NOACTION) {
+      int ai_flags[2];
+      ai_flags[0] = sfd->para.socket.ip.ai_flags[0];
+      ai_flags[1] = sfd->para.socket.ip.ai_flags[1];
+      if (!(ai_flags[1] & AI_PASSIVE))
+	 ai_flags[0] |= AI_PASSIVE;
+      result =
+	 xioresolve(NULL, portname, pf, socktype, ipproto, &us, &uslen, ai_flags);
+      if (result != STAT_OK) {
+	 Error("error resolving bind option");
+	 return STAT_NORETRY;
+      }
+      pf = us.soa.sa_family;
+#endif /* WITH_IP4 || WITH_IP6*/
 #if WITH_IP4
    } else if (pf == PF_INET) {
       us.ip4.sin_port = parseport(portname, ipproto);
@@ -323,7 +344,9 @@ int xioopen_ipdgram_listen(
       us.ip6.sin6_port = parseport(portname, ipproto);
 #endif
    } else {
+#if 1
       Error1("xioopen_ipdgram_listen(): unknown address family %d", pf);
+#endif
    }
 
    return _xioopen_ipdgram_listen(&xfd->stream, xioflags, &us, uslen,
diff --git a/xioopts.c b/xioopts.c
index 4b651aa..abf4ffe 100644
--- a/xioopts.c
+++ b/xioopts.c
@@ -3252,6 +3252,7 @@ int retropt_bind(struct opt *opts,
 				   UNIX (or'd): 1..tight
 						2..abstract
 						4..templatename
+				   0..generic addr spec
 				*/
 		 const int ai_flags[2])
 {
@@ -3271,10 +3272,13 @@ int retropt_bind(struct opt *opts,
    }
    bindp = bindname;
 
-   switch (af) {
+#if WITH_IP4 && WITH_IP6
+   /* Try to derive address family from string */
+   if (af == AF_UNSPEC && bindname[0] == '[')
+      af = AF_INET6;
+#endif /* WITH_IP4 && WITH_IP6 */
 
-   case AF_UNSPEC:
-      {
+   if (feats == 0) {
 	 size_t p = 0;
 	 dalan(bindname, (uint8_t *)sa->sa_data, &p, *salen-sizeof(sa->sa_family), 'i');
 	 *salen = p + sizeof(sa->sa_family);
@@ -3286,10 +3290,13 @@ int retropt_bind(struct opt *opts,
 #if HAVE_STRUCT_SOCKADDR_SALEN
 	 sa->sa_len = *salen;
 #endif
-      }
-      break;
+	 return STAT_OK;
+   }
+
+   switch (af) {
 
 #if WITH_IP4 || WITH_IP6 || WITH_VSOCK
+   case AF_UNSPEC:
 #if WITH_VSOCK
    case AF_VSOCK:
 #endif
@@ -3324,7 +3331,7 @@ int retropt_bind(struct opt *opts,
       ai_flags2[0] = ai_flags[0];
       ai_flags2[1] = ai_flags[1];
       if (!(ai_flags2[1] & AI_PASSIVE))
-      ai_flags2[0] |= AI_PASSIVE;
+	 ai_flags2[0] |= AI_PASSIVE;
 
       if ((result =
 	   xioresolve(hostname[0]!='\0'?hostname:NULL, portp,