diff --git a/conf.c b/conf.c
index b275886..9f1cd83 100644
--- a/conf.c
+++ b/conf.c
@@ -116,11 +116,10 @@ static int parse_port_range(const char *s, char **endptr,
 static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 		       struct fwd_ports *fwd)
 {
-	char addr_buf[sizeof(struct in6_addr)] = { 0 }, *addr = addr_buf;
+	union inany_addr addr_buf = inany_any6, *addr = &addr_buf;
 	char buf[BUFSIZ], *spec, *ifname = NULL, *p;
 	bool exclude_only = true, bound_one = false;
 	uint8_t exclude[PORT_BITMAP_SIZE] = { 0 };
-	sa_family_t af = AF_UNSPEC;
 	unsigned i;
 	int ret;
 
@@ -166,15 +165,13 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 
 			bitmap_set(fwd->map, i);
 			if (optname == 't') {
-				ret = tcp_sock_init(c, AF_UNSPEC, NULL, NULL,
-						    i);
+				ret = tcp_sock_init(c, NULL, NULL, i);
 				if (ret == -ENFILE || ret == -EMFILE)
 					goto enfile;
 				if (!ret)
 					bound_one = true;
 			} else if (optname == 'u') {
-				ret = udp_sock_init(c, 0, AF_UNSPEC, NULL, NULL,
-						    i);
+				ret = udp_sock_init(c, 0, NULL, NULL, i);
 				if (ret == -ENFILE || ret == -EMFILE)
 					goto enfile;
 				if (!ret)
@@ -218,6 +215,9 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 		if (ifname == buf + 1) {	/* Interface without address */
 			addr = NULL;
 		} else {
+			struct in6_addr a6;
+			struct in_addr a4;
+
 			p = buf;
 
 			/* Allow square brackets for IPv4 too for convenience */
@@ -226,10 +226,10 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 				p++;
 			}
 
-			if (inet_pton(AF_INET, p, addr))
-				af = AF_INET;
-			else if (inet_pton(AF_INET6, p, addr))
-				af = AF_INET6;
+			if (inet_pton(AF_INET, p, &a4))
+				inany_from_af(addr, AF_INET, &a4);
+			else if (inet_pton(AF_INET6, p, &a6))
+				inany_from_af(addr, AF_INET6, &a6);
 			else
 				goto bad;
 		}
@@ -276,13 +276,13 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 			bitmap_set(fwd->map, i);
 
 			if (optname == 't') {
-				ret = tcp_sock_init(c, af, addr, ifname, i);
+				ret = tcp_sock_init(c, addr, ifname, i);
 				if (ret == -ENFILE || ret == -EMFILE)
 					goto enfile;
 				if (!ret)
 					bound_one = true;
 			} else if (optname == 'u') {
-				ret = udp_sock_init(c, 0, af, addr, ifname, i);
+				ret = udp_sock_init(c, 0, addr, ifname, i);
 				if (ret == -ENFILE || ret == -EMFILE)
 					goto enfile;
 				if (!ret)
@@ -338,9 +338,9 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 
 			ret = 0;
 			if (optname == 't')
-				ret = tcp_sock_init(c, af, addr, ifname, i);
+				ret = tcp_sock_init(c, addr, ifname, i);
 			else if (optname == 'u')
-				ret = udp_sock_init(c, 0, af, addr, ifname, i);
+				ret = udp_sock_init(c, 0, addr, ifname, i);
 			if (ret)
 				goto bind_fail;
 		}
diff --git a/tcp.c b/tcp.c
index 49e0cfe..6ca3700 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2273,17 +2273,16 @@ void tcp_sock_handler(const struct ctx *c, union epoll_ref ref,
 }
 
 /**
- * tcp_sock_init_af() - Initialise listening socket for a given af and port
+ * tcp_sock_init_one() - Initialise listening socket for address and port
  * @c:		Execution context
- * @af:		Address family to listen on
- * @port:	Port, host order
- * @addr:	Pointer to address for binding, NULL if not configured
+ * @addr:	Pointer to address for binding, NULL for dual stack any
  * @ifname:	Name of interface to bind to, NULL if not configured
+ * @port:	Port, host order
  *
  * Return: fd for the new listening socket, negative error code on failure
  */
-static int tcp_sock_init_af(const struct ctx *c, sa_family_t af, in_port_t port,
-			    const void *addr, const char *ifname)
+static int tcp_sock_init_one(const struct ctx *c, const union inany_addr *addr,
+			     const char *ifname, in_port_t port)
 {
 	union tcp_listen_epoll_ref tref = {
 		.port = port,
@@ -2291,24 +2290,13 @@ static int tcp_sock_init_af(const struct ctx *c, sa_family_t af, in_port_t port,
 	};
 	int s;
 
-	if (af == AF_UNSPEC) {
-		ASSERT(!addr);
-		s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_HOST, NULL,
+	s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_HOST, addr,
 				ifname, port, tref.u32);
-	} else {
-		union inany_addr aany = af == AF_INET ? inany_any4 : inany_any6;
-
-		if (addr)
-			inany_from_af(&aany, af, addr);
-
-		s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_HOST, &aany,
-				ifname, port, tref.u32);
-	}
 
 	if (c->tcp.fwd_in.mode == FWD_AUTO) {
-		if (af == AF_INET  || af == AF_UNSPEC)
+		if (!addr || inany_v4(addr))
 			tcp_sock_init_ext[port][V4] = s < 0 ? -1 : s;
-		if (af == AF_INET6 || af == AF_UNSPEC)
+		if (!addr || !inany_v4(addr))
 			tcp_sock_init_ext[port][V6] = s < 0 ? -1 : s;
 	}
 
@@ -2322,31 +2310,32 @@ static int tcp_sock_init_af(const struct ctx *c, sa_family_t af, in_port_t port,
 /**
  * tcp_sock_init() - Create listening sockets for a given host ("inbound") port
  * @c:		Execution context
- * @af:		Address family to select a specific IP version, or AF_UNSPEC
  * @addr:	Pointer to address for binding, NULL if not configured
  * @ifname:	Name of interface to bind to, NULL if not configured
  * @port:	Port, host order
  *
  * Return: 0 on (partial) success, negative error code on (complete) failure
  */
-int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
+int tcp_sock_init(const struct ctx *c, const union inany_addr *addr,
 		  const char *ifname, in_port_t port)
 {
 	int r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
 
 	ASSERT(!c->no_tcp);
 
-	if (af == AF_UNSPEC && c->ifi4 && c->ifi6)
+	if (!addr && c->ifi4 && c->ifi6)
 		/* Attempt to get a dual stack socket */
-		if (tcp_sock_init_af(c, AF_UNSPEC, port, addr, ifname) >= 0)
+		if (tcp_sock_init_one(c, NULL, ifname, port) >= 0)
 			return 0;
 
 	/* Otherwise create a socket per IP version */
-	if ((af == AF_INET  || af == AF_UNSPEC) && c->ifi4)
-		r4 = tcp_sock_init_af(c, AF_INET, port, addr, ifname);
+	if ((!addr || inany_v4(addr)) && c->ifi4)
+		r4 = tcp_sock_init_one(c, addr ? addr : &inany_any4,
+				       ifname, port);
 
-	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6)
-		r6 = tcp_sock_init_af(c, AF_INET6, port, addr, ifname);
+	if ((!addr || !inany_v4(addr)) && c->ifi6)
+		r6 = tcp_sock_init_one(c, addr ? addr : &inany_any6,
+				       ifname, port);
 
 	if (IN_INTERVAL(0, FD_REF_MAX, r4) || IN_INTERVAL(0, FD_REF_MAX, r6))
 		return 0;
@@ -2629,7 +2618,7 @@ static void tcp_port_rebind(struct ctx *c, bool outbound)
 			if (outbound)
 				tcp_ns_sock_init(c, port);
 			else
-				tcp_sock_init(c, AF_UNSPEC, NULL, NULL, port);
+				tcp_sock_init(c, NULL, NULL, port);
 		}
 	}
 }
diff --git a/tcp.h b/tcp.h
index 5585924..cf30744 100644
--- a/tcp.h
+++ b/tcp.h
@@ -18,7 +18,7 @@ void tcp_sock_handler(const struct ctx *c, union epoll_ref ref,
 int tcp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 		    const void *saddr, const void *daddr,
 		    const struct pool *p, int idx, const struct timespec *now);
-int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
+int tcp_sock_init(const struct ctx *c, const union inany_addr *addr,
 		  const char *ifname, in_port_t port);
 int tcp_init(struct ctx *c);
 void tcp_timer(struct ctx *c, const struct timespec *now);
diff --git a/udp.c b/udp.c
index b3d4a64..08faaec 100644
--- a/udp.c
+++ b/udp.c
@@ -785,15 +785,14 @@ int udp_tap_handler(const struct ctx *c, uint8_t pif,
  * udp_sock_init() - Initialise listening sockets for a given port
  * @c:		Execution context
  * @ns:		In pasta mode, if set, bind with loopback address in namespace
- * @af:		Address family to select a specific IP version, or AF_UNSPEC
  * @addr:	Pointer to address for binding, NULL if not configured
  * @ifname:	Name of interface to bind to, NULL if not configured
  * @port:	Port, host order
  *
  * Return: 0 on (partial) success, negative error code on (complete) failure
  */
-int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
-		  const void *addr, const char *ifname, in_port_t port)
+int udp_sock_init(const struct ctx *c, int ns, const union inany_addr *addr,
+		  const char *ifname, in_port_t port)
 {
 	union udp_listen_epoll_ref uref = {
 		.pif = ns ? PIF_SPLICE : PIF_HOST,
@@ -803,11 +802,9 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 
 	ASSERT(!c->no_udp);
 
-	if (af == AF_UNSPEC && c->ifi4 && c->ifi6 && !ns) {
+	if (!addr && c->ifi4 && c->ifi6 && !ns) {
 		int s;
 
-		ASSERT(!addr);
-
 		/* Attempt to get a dual stack socket */
 		s = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST,
 				NULL, ifname, port, uref.u32);
@@ -817,15 +814,11 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 			return 0;
 	}
 
-	if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) {
+	if ((!addr || inany_v4(addr)) && c->ifi4) {
 		if (!ns) {
-			union inany_addr aany = inany_any4;
-
-			if (addr)
-				inany_from_af(&aany, AF_INET, addr);
-
 			r4 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST,
-					 &aany, ifname, port, uref.u32);
+					 addr ? addr : &inany_any4, ifname,
+					 port, uref.u32);
 
 			udp_splice_init[V4][port] = r4 < 0 ? -1 : r4;
 		} else {
@@ -836,15 +829,11 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 		}
 	}
 
-	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) {
+	if ((!addr || !inany_v4(addr)) && c->ifi6) {
 		if (!ns) {
-			union inany_addr aany = inany_any6;
-
-			if (addr)
-				inany_from_af(&aany, AF_INET6, addr);
-
 			r6 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST,
-					 &aany, ifname, port, uref.u32);
+					 addr ? addr : &inany_any6, ifname,
+					 port, uref.u32);
 
 			udp_splice_init[V6][port] = r6 < 0 ? -1 : r6;
 		} else {
@@ -918,7 +907,7 @@ static void udp_port_rebind(struct ctx *c, bool outbound)
 
 		if ((c->ifi4 && socks[V4][port] == -1) ||
 		    (c->ifi6 && socks[V6][port] == -1))
-			udp_sock_init(c, outbound, AF_UNSPEC, NULL, NULL, port);
+			udp_sock_init(c, outbound, NULL, NULL, port);
 	}
 }
 
diff --git a/udp.h b/udp.h
index a8e76bf..de2df6d 100644
--- a/udp.h
+++ b/udp.h
@@ -16,8 +16,8 @@ void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref,
 int udp_tap_handler(const struct ctx *c, uint8_t pif,
 		    sa_family_t af, const void *saddr, const void *daddr,
 		    const struct pool *p, int idx, const struct timespec *now);
-int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
-		  const void *addr, const char *ifname, in_port_t port);
+int udp_sock_init(const struct ctx *c, int ns, const union inany_addr *addr,
+		  const char *ifname, in_port_t port);
 int udp_init(struct ctx *c);
 void udp_timer(struct ctx *c, const struct timespec *now);
 void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s);