diff --git a/lib_acl/src/master/template/acl_udp_server.c b/lib_acl/src/master/template/acl_udp_server.c
index 85e0fb449..25a85e1c9 100644
--- a/lib_acl/src/master/template/acl_udp_server.c
+++ b/lib_acl/src/master/template/acl_udp_server.c
@@ -317,8 +317,9 @@ static void server_add_addrs(UDP_SERVER *server, ACL_HTABLE *addrs)
 		ACL_VSTREAM *stream = server_bind_one(ptr);
 
 		if (stream == NULL) {
-			acl_msg_error("%s(%d): bind %s error %s", __FUNCTION__,
-				__LINE__, ptr, acl_last_serror());
+			acl_msg_error("%s(%d), %s: bind %s error %s",
+				__FILE__, __LINE__, __FUNCTION__,
+				ptr, acl_last_serror());
 			continue;
 		}
 
@@ -330,7 +331,8 @@ static void server_add_addrs(UDP_SERVER *server, ACL_HTABLE *addrs)
 		acl_event_enable_read(server->event, stream, 0,
 			udp_server_read, server);
 
-		acl_msg_info("bind %s addr ok, fd %d",
+		acl_msg_info("%s(%d), %s: bind %s addr ok, fd %d",
+			__FILE__, __LINE__, __FUNCTION__,
 			ACL_VSTREAM_LOCAL(stream), SOCK(stream));
 	}
 }
@@ -709,7 +711,8 @@ static ACL_VSTREAM *server_bind_one(const char *addr)
 
 	fd = acl_udp_bind(addr, flag);
 	if (fd == ACL_SOCKET_INVALID) {
-		acl_msg_warn("bind %s error %s", addr, acl_last_serror());
+		acl_msg_warn("%s(%d), %s: bind %s error %s", __FILE__,
+			__LINE__, __FUNCTION__, addr, acl_last_serror());
 		return NULL;
 	}
 
diff --git a/lib_acl/src/net/listen/acl_sane_bind.c b/lib_acl/src/net/listen/acl_sane_bind.c
index d39397889..a0f0f66cc 100644
--- a/lib_acl/src/net/listen/acl_sane_bind.c
+++ b/lib_acl/src/net/listen/acl_sane_bind.c
@@ -220,27 +220,30 @@ static ACL_SOCKET find_bind(const char *addr, unsigned flag,
 }
 
 ACL_SOCKET acl_sane_bind(const char *addr, unsigned flag,
-	int socktype, int *family)
+	int socktype, int *family_ptr)
 {
 	ACL_SOCKET fd;
+	int family = PF_UNSPEC;
 
 	if (acl_valid_ipv4_hostaddr(addr, 0)) {
-		if (family) {
-			*family = AF_INET;
-		}
-		fd = bind_addr(addr, flag, socktype, AF_INET);
+		family = PF_INET;
+		fd = bind_addr(addr, flag, socktype, PF_INET);
 	} else if (acl_valid_ipv6_hostaddr(addr, 0)) {
-		if (family) {
-			*family = AF_INET6;
-		}
-		fd = bind_addr(addr, flag, socktype, AF_INET6);
+		family = PF_INET6;
+		fd = bind_addr(addr, flag, socktype, PF_INET6);
 	} else {
-		fd = find_bind(addr, flag, socktype, family);
+		fd = find_bind(addr, flag, socktype, &family);
+	}
+
+	if (family_ptr) {
+		*family_ptr = family;
 	}
 
 	if (fd == ACL_SOCKET_INVALID) {
-		acl_msg_error("%s(%d): bind %s error %s",
-			__FILE__, __LINE__, addr, acl_last_serror());
+		acl_msg_error("%s(%d): bind %s error %s, family=%s",
+			__FILE__, __LINE__, addr, acl_last_serror(),
+			family == PF_INET ? "PF_INET" : (family == PF_INET6 ?
+				"PF_INET6" : "UNKNOWN"));
 		return ACL_SOCKET_INVALID;
 	}