diff --git a/src/basic/hostname-util.c b/src/basic/hostname-util.c
index 82cd37b154..e1e3d1b061 100644
--- a/src/basic/hostname-util.c
+++ b/src/basic/hostname-util.c
@@ -98,28 +98,24 @@ bool valid_ldh_char(char c) {
                 c == '-';
 }
 
-/**
- * Check if s looks like a valid hostname or FQDN. This does not do
- * full DNS validation, but only checks if the name is composed of
- * allowed characters and the length is not above the maximum allowed
- * by Linux (c.f. dns_name_is_valid()). Trailing dot is allowed if
- * allow_trailing_dot is true and at least two components are present
- * in the name. Note that due to the restricted charset and length
- * this call is substantially more conservative than
- * dns_name_is_valid().
- */
-bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
+bool hostname_is_valid(const char *s, ValidHostnameFlags flags) {
         unsigned n_dots = 0;
         const char *p;
         bool dot, hyphen;
 
+        /* Check if s looks like a valid hostname or FQDN. This does not do full DNS validation, but only
+         * checks if the name is composed of allowed characters and the length is not above the maximum
+         * allowed by Linux (c.f. dns_name_is_valid()). A trailing dot is allowed if
+         * VALID_HOSTNAME_TRAILING_DOT flag is set and at least two components are present in the name. Note
+         * that due to the restricted charset and length this call is substantially more conservative than
+         * dns_name_is_valid(). Doesn't accept empty hostnames, hostnames with leading dots, and hostnames
+         * with multiple dots in a sequence. Doesn't allow hyphens at the beginning or end of label. */
+
         if (isempty(s))
                 return false;
 
-        /* Doesn't accept empty hostnames, hostnames with
-         * leading dots, and hostnames with multiple dots in a
-         * sequence. Also ensures that the length stays below
-         * HOST_NAME_MAX. */
+        if (streq(s, ".host")) /* Used by the container logic to denote the "root container" */
+                return FLAGS_SET(flags, VALID_HOSTNAME_DOT_HOST);
 
         for (p = s, dot = hyphen = true; *p; p++)
                 if (*p == '.') {
@@ -145,14 +141,13 @@ bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
                         hyphen = false;
                 }
 
-        if (dot && (n_dots < 2 || !allow_trailing_dot))
+        if (dot && (n_dots < 2 || !FLAGS_SET(flags, VALID_HOSTNAME_TRAILING_DOT)))
                 return false;
         if (hyphen)
                 return false;
 
-        if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on
-                                  * Linux, but DNS allows domain names
-                                  * up to 255 characters */
+        if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on Linux, but DNS allows domain names up to
+                                  * 255 characters */
                 return false;
 
         return true;
@@ -243,7 +238,7 @@ int shorten_overlong(const char *s, char **ret) {
         if (!h)
                 return -ENOMEM;
 
-        if (hostname_is_valid(h, false)) {
+        if (hostname_is_valid(h, 0)) {
                 *ret = h;
                 return 0;
         }
@@ -254,7 +249,7 @@ int shorten_overlong(const char *s, char **ret) {
 
         strshorten(h, HOST_NAME_MAX);
 
-        if (!hostname_is_valid(h, false)) {
+        if (!hostname_is_valid(h, 0)) {
                 free(h);
                 return -EDOM;
         }
@@ -287,7 +282,7 @@ int read_etc_hostname_stream(FILE *f, char **ret) {
 
                         hostname_cleanup(p); /* normalize the hostname */
 
-                        if (!hostname_is_valid(p, true)) /* check that the hostname we return is valid */
+                        if (!hostname_is_valid(p, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */
                                 return -EBADMSG;
 
                         copy = strdup(p);
diff --git a/src/basic/hostname-util.h b/src/basic/hostname-util.h
index 34819c2953..fe417297ee 100644
--- a/src/basic/hostname-util.h
+++ b/src/basic/hostname-util.h
@@ -14,10 +14,14 @@ char* gethostname_short_malloc(void);
 int gethostname_strict(char **ret);
 
 bool valid_ldh_char(char c) _const_;
-bool hostname_is_valid(const char *s, bool allow_trailing_dot) _pure_;
-char* hostname_cleanup(char *s);
 
-#define machine_name_is_valid(s) hostname_is_valid(s, false)
+typedef enum ValidHostnameFlags {
+        VALID_HOSTNAME_TRAILING_DOT = 1 << 0,   /* Accept trailing dot on multi-label names */
+        VALID_HOSTNAME_DOT_HOST     = 1 << 1,   /* Accept ".host" as valid hostname */
+} ValidHostnameFlags;
+
+bool hostname_is_valid(const char *s, ValidHostnameFlags flags) _pure_;
+char* hostname_cleanup(char *s);
 
 bool is_localhost(const char *hostname);
 
diff --git a/src/basic/util.c b/src/basic/util.c
index b080ce4e96..7c708eb3be 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -165,7 +165,7 @@ int container_get_leader(const char *machine, pid_t *pid) {
                 return 0;
         }
 
-        if (!machine_name_is_valid(machine))
+        if (!hostname_is_valid(machine, 0))
                 return -EINVAL;
 
         p = strjoina("/run/systemd/machines/", machine);
diff --git a/src/core/hostname-setup.c b/src/core/hostname-setup.c
index 867ea19905..4e20e764a3 100644
--- a/src/core/hostname-setup.c
+++ b/src/core/hostname-setup.c
@@ -24,7 +24,7 @@ int hostname_setup(void) {
         if (r < 0)
                 log_warning_errno(r, "Failed to retrieve system hostname from kernel command line, ignoring: %m");
         else if (r > 0) {
-                if (hostname_is_valid(b, true))
+                if (hostname_is_valid(b, VALID_HOSTNAME_TRAILING_DOT))
                         hn = b;
                 else  {
                         log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", b);
diff --git a/src/firstboot/firstboot.c b/src/firstboot/firstboot.c
index 742b43f9fc..48baae3f89 100644
--- a/src/firstboot/firstboot.c
+++ b/src/firstboot/firstboot.c
@@ -493,7 +493,7 @@ static int prompt_hostname(void) {
                         break;
                 }
 
-                if (!hostname_is_valid(h, true)) {
+                if (!hostname_is_valid(h, VALID_HOSTNAME_TRAILING_DOT)) {
                         log_error("Specified hostname invalid.");
                         continue;
                 }
@@ -1135,7 +1135,7 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_HOSTNAME:
-                        if (!hostname_is_valid(optarg, true))
+                        if (!hostname_is_valid(optarg, VALID_HOSTNAME_TRAILING_DOT))
                                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                        "Host name %s is not valid.", optarg);
 
diff --git a/src/hostname/hostnamectl.c b/src/hostname/hostnamectl.c
index 0d39e9176f..de6eb9ea2f 100644
--- a/src/hostname/hostnamectl.c
+++ b/src/hostname/hostnamectl.c
@@ -248,7 +248,7 @@ static int set_hostname(int argc, char **argv, void *userdata) {
                 /* If the passed hostname is already valid, then assume the user doesn't know anything about pretty
                  * hostnames, so let's unset the pretty hostname, and just set the passed hostname as static/dynamic
                  * hostname. */
-                if (arg_static && hostname_is_valid(hostname, true))
+                if (arg_static && hostname_is_valid(hostname, VALID_HOSTNAME_TRAILING_DOT))
                         p = ""; /* No pretty hostname (as it is redundant), just a static one */
                 else
                         p = hostname; /* Use the passed name as pretty hostname */
diff --git a/src/hostname/hostnamed.c b/src/hostname/hostnamed.c
index a1794bdab1..a0dc25c834 100644
--- a/src/hostname/hostnamed.c
+++ b/src/hostname/hostnamed.c
@@ -596,7 +596,7 @@ static int method_set_hostname(sd_bus_message *m, void *userdata, sd_bus_error *
         if (isempty(name))
                 name = FALLBACK_HOSTNAME;
 
-        if (!hostname_is_valid(name, false))
+        if (!hostname_is_valid(name, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid hostname '%s'", name);
 
         assert_se(uname(&u) >= 0);
@@ -650,7 +650,7 @@ static int method_set_static_hostname(sd_bus_message *m, void *userdata, sd_bus_
         if (streq_ptr(name, c->data[PROP_STATIC_HOSTNAME]))
                 return sd_bus_reply_method_return(m, NULL);
 
-        if (!isempty(name) && !hostname_is_valid(name, false))
+        if (!isempty(name) && !hostname_is_valid(name, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid static hostname '%s'", name);
 
         r = bus_verify_polkit_async(
diff --git a/src/import/export.c b/src/import/export.c
index 83990df64c..b8507330ac 100644
--- a/src/import/export.c
+++ b/src/import/export.c
@@ -65,7 +65,7 @@ static int export_tar(int argc, char *argv[], void *userdata) {
         _cleanup_close_ int open_fd = -1;
         int r, fd;
 
-        if (machine_name_is_valid(argv[1])) {
+        if (hostname_is_valid(argv[1], 0)) {
                 r = image_find(IMAGE_MACHINE, argv[1], &image);
                 if (r == -ENOENT)
                         return log_error_errno(r, "Machine image %s not found.", argv[1]);
@@ -141,7 +141,7 @@ static int export_raw(int argc, char *argv[], void *userdata) {
         _cleanup_close_ int open_fd = -1;
         int r, fd;
 
-        if (machine_name_is_valid(argv[1])) {
+        if (hostname_is_valid(argv[1], 0)) {
                 r = image_find(IMAGE_MACHINE, argv[1], &image);
                 if (r == -ENOENT)
                         return log_error_errno(r, "Machine image %s not found.", argv[1]);
diff --git a/src/import/import-fs.c b/src/import/import-fs.c
index 3b43ea112d..a22eef8255 100644
--- a/src/import/import-fs.c
+++ b/src/import/import-fs.c
@@ -126,7 +126,7 @@ static int import_fs(int argc, char *argv[], void *userdata) {
         local = empty_or_dash_to_null(local);
 
         if (local) {
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local image name '%s' is not valid.",
                                                local);
diff --git a/src/import/import-raw.c b/src/import/import-raw.c
index 9f5c13ba16..c0869ffcf9 100644
--- a/src/import/import-raw.c
+++ b/src/import/import-raw.c
@@ -393,7 +393,7 @@ int raw_import_start(RawImport *i, int fd, const char *local, bool force_local,
         assert(fd >= 0);
         assert(local);
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return -EINVAL;
 
         if (i->input_fd >= 0)
diff --git a/src/import/import-tar.c b/src/import/import-tar.c
index 9f68d45eac..d68ce91613 100644
--- a/src/import/import-tar.c
+++ b/src/import/import-tar.c
@@ -329,7 +329,7 @@ int tar_import_start(TarImport *i, int fd, const char *local, bool force_local,
         assert(fd >= 0);
         assert(local);
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return -EINVAL;
 
         if (i->input_fd >= 0)
diff --git a/src/import/import.c b/src/import/import.c
index eade0f0ec8..9ea8e7f16d 100644
--- a/src/import/import.c
+++ b/src/import/import.c
@@ -64,7 +64,7 @@ static int import_tar(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local image name '%s' is not valid.",
                                                local);
@@ -159,7 +159,7 @@ static int import_raw(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local image name '%s' is not valid.",
                                                local);
diff --git a/src/import/importd.c b/src/import/importd.c
index 63f80e0e38..b5cff4aca8 100644
--- a/src/import/importd.c
+++ b/src/import/importd.c
@@ -717,7 +717,7 @@ static int method_import_tar_or_raw(sd_bus_message *msg, void *userdata, sd_bus_
         if (!S_ISREG(st.st_mode) && !S_ISFIFO(st.st_mode))
                 return -EINVAL;
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
                                          "Local name %s is invalid", local);
 
@@ -787,7 +787,7 @@ static int method_import_fs(sd_bus_message *msg, void *userdata, sd_bus_error *e
         if (r < 0)
                 return r;
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
                                          "Local name %s is invalid", local);
 
@@ -852,7 +852,7 @@ static int method_export_tar_or_raw(sd_bus_message *msg, void *userdata, sd_bus_
         if (r < 0)
                 return r;
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
                                          "Local name %s is invalid", local);
 
@@ -932,7 +932,7 @@ static int method_pull_tar_or_raw(sd_bus_message *msg, void *userdata, sd_bus_er
 
         if (isempty(local))
                 local = NULL;
-        else if (!machine_name_is_valid(local))
+        else if (!hostname_is_valid(local, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
                                          "Local name %s is invalid", local);
 
diff --git a/src/import/pull-raw.c b/src/import/pull-raw.c
index 7956ef0395..4a2bab3d07 100644
--- a/src/import/pull-raw.c
+++ b/src/import/pull-raw.c
@@ -651,7 +651,7 @@ int raw_pull_start(
         if (!http_url_is_valid(url))
                 return -EINVAL;
 
-        if (local && !machine_name_is_valid(local))
+        if (local && !hostname_is_valid(local, 0))
                 return -EINVAL;
 
         if (i->raw_job)
diff --git a/src/import/pull-tar.c b/src/import/pull-tar.c
index 72e5b8be27..bbbd0f57a0 100644
--- a/src/import/pull-tar.c
+++ b/src/import/pull-tar.c
@@ -481,7 +481,7 @@ int tar_pull_start(
         if (!http_url_is_valid(url))
                 return -EINVAL;
 
-        if (local && !machine_name_is_valid(local))
+        if (local && !hostname_is_valid(local, 0))
                 return -EINVAL;
 
         if (i->tar_job)
diff --git a/src/import/pull.c b/src/import/pull.c
index 9aff377b93..a4cec9448e 100644
--- a/src/import/pull.c
+++ b/src/import/pull.c
@@ -72,7 +72,7 @@ static int pull_tar(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local image name '%s' is not valid.",
                                                local);
@@ -158,7 +158,7 @@ static int pull_raw(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local image name '%s' is not valid.",
                                                local);
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index 946f74d535..e94fb4dafb 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -1981,7 +1981,7 @@ _public_ int sd_journal_open_container(sd_journal **ret, const char *machine, in
         assert_return(machine, -EINVAL);
         assert_return(ret, -EINVAL);
         assert_return((flags & ~OPEN_CONTAINER_ALLOWED_FLAGS) == 0, -EINVAL);
-        assert_return(machine_name_is_valid(machine), -EINVAL);
+        assert_return(hostname_is_valid(machine, 0), -EINVAL);
 
         p = strjoina("/run/systemd/machines/", machine);
         r = parse_env_file(NULL, p,
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index f47a542483..252a01add6 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -540,7 +540,7 @@ int sd_dhcp_client_set_hostname(
 
         /* Make sure hostnames qualify as DNS and as Linux hostnames */
         if (hostname &&
-            !(hostname_is_valid(hostname, false) && dns_name_is_valid(hostname) > 0))
+            !(hostname_is_valid(hostname, 0) && dns_name_is_valid(hostname) > 0))
                 return -EINVAL;
 
         return free_and_strdup(&client->hostname, hostname);
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 97fd5fd4fb..e068e0dc91 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -407,7 +407,7 @@ int sd_dhcp6_client_set_fqdn(
 
         /* Make sure FQDN qualifies as DNS and as Linux hostname */
         if (fqdn &&
-            !(hostname_is_valid(fqdn, false) && dns_name_is_valid(fqdn) > 0))
+            !(hostname_is_valid(fqdn, 0) && dns_name_is_valid(fqdn) > 0))
                 return -EINVAL;
 
         return free_and_strdup(&client->fqdn, fqdn);
diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c
index b8d4dc8d95..da7827015a 100644
--- a/src/libsystemd/sd-bus/sd-bus.c
+++ b/src/libsystemd/sd-bus/sd-bus.c
@@ -973,7 +973,7 @@ static int parse_container_unix_address(sd_bus *b, const char **p, char **guid)
                 return -EINVAL;
 
         if (machine) {
-                if (!streq(machine, ".host") && !machine_name_is_valid(machine))
+                if (!hostname_is_valid(machine, VALID_HOSTNAME_DOT_HOST))
                         return -EINVAL;
 
                 free_and_replace(b->machine, machine);
@@ -1448,7 +1448,7 @@ int bus_set_address_system_remote(sd_bus *b, const char *host) {
                 }
 
                 if (!in_charset(p, "0123456789") || *p == '\0') {
-                        if (!machine_name_is_valid(p) || got_forward_slash)
+                        if (!hostname_is_valid(p, 0) || got_forward_slash)
                                 return -EINVAL;
 
                         m = TAKE_PTR(p);
@@ -1463,7 +1463,7 @@ int bus_set_address_system_remote(sd_bus *b, const char *host) {
 interpret_port_as_machine_old_syntax:
                 /* Let's make sure this is not a port of some kind,
                  * and is a valid machine name. */
-                if (!in_charset(m, "0123456789") && machine_name_is_valid(m))
+                if (!in_charset(m, "0123456789") && hostname_is_valid(m, 0))
                         c = strjoina(",argv", p ? "7" : "5", "=--machine=", m);
         }
 
@@ -1538,7 +1538,7 @@ _public_ int sd_bus_open_system_machine(sd_bus **ret, const char *machine) {
 
         assert_return(machine, -EINVAL);
         assert_return(ret, -EINVAL);
-        assert_return(streq(machine, ".host") || machine_name_is_valid(machine), -EINVAL);
+        assert_return(hostname_is_valid(machine, VALID_HOSTNAME_DOT_HOST), -EINVAL);
 
         r = sd_bus_new(&b);
         if (r < 0)
diff --git a/src/libsystemd/sd-login/sd-login.c b/src/libsystemd/sd-login/sd-login.c
index 1fc379512f..d15dafbd95 100644
--- a/src/libsystemd/sd-login/sd-login.c
+++ b/src/libsystemd/sd-login/sd-login.c
@@ -847,7 +847,7 @@ _public_ int sd_get_machine_names(char ***machines) {
 
                 /* Filter out the unit: symlinks */
                 for (a = b = l; *a; a++) {
-                        if (startswith(*a, "unit:") || !machine_name_is_valid(*a))
+                        if (startswith(*a, "unit:") || !hostname_is_valid(*a, 0))
                                 free(*a);
                         else {
                                 *b = *a;
@@ -877,7 +877,7 @@ _public_ int sd_machine_get_class(const char *machine, char **class) {
                 if (!c)
                         return -ENOMEM;
         } else {
-                if (!machine_name_is_valid(machine))
+                if (!hostname_is_valid(machine, 0))
                         return -EINVAL;
 
                 p = strjoina("/run/systemd/machines/", machine);
@@ -899,7 +899,7 @@ _public_ int sd_machine_get_ifindices(const char *machine, int **ret_ifindices)
         const char *p;
         int r;
 
-        assert_return(machine_name_is_valid(machine), -EINVAL);
+        assert_return(hostname_is_valid(machine, 0), -EINVAL);
 
         p = strjoina("/run/systemd/machines/", machine);
         r = parse_env_file(NULL, p, "NETIF", &netif_line);
diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c
index 4a3279d264..3c839455b6 100644
--- a/src/machine/machinectl.c
+++ b/src/machine/machinectl.c
@@ -1561,7 +1561,7 @@ static int make_service_name(const char *name, char **ret) {
         assert(name);
         assert(ret);
 
-        if (!machine_name_is_valid(name))
+        if (!hostname_is_valid(name, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Invalid machine name %s.", name);
 
@@ -1881,7 +1881,7 @@ static int import_tar(int argc, char *argv[], void *userdata) {
 
         local = ll;
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Local name %s is not a suitable machine name.",
                                        local);
@@ -1941,7 +1941,7 @@ static int import_raw(int argc, char *argv[], void *userdata) {
 
         local = ll;
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Local name %s is not a suitable machine name.",
                                        local);
@@ -1995,7 +1995,7 @@ static int import_fs(int argc, char *argv[], void *userdata) {
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Need either path or local name.");
 
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Local name %s is not a suitable machine name.",
                                        local);
@@ -2048,7 +2048,7 @@ static int export_tar(int argc, char *argv[], void *userdata) {
         assert(bus);
 
         local = argv[1];
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Machine name %s is not valid.", local);
 
@@ -2090,7 +2090,7 @@ static int export_raw(int argc, char *argv[], void *userdata) {
         assert(bus);
 
         local = argv[1];
-        if (!machine_name_is_valid(local))
+        if (!hostname_is_valid(local, 0))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Machine name %s is not valid.", local);
 
@@ -2155,7 +2155,7 @@ static int pull_tar(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local name %s is not a suitable machine name.",
                                                local);
@@ -2211,7 +2211,7 @@ static int pull_raw(int argc, char *argv[], void *userdata) {
 
                 local = ll;
 
-                if (!machine_name_is_valid(local))
+                if (!hostname_is_valid(local, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Local name %s is not a suitable machine name.",
                                                local);
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 494813e334..501db643f8 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -239,7 +239,7 @@ static int method_create_or_register_machine(Manager *manager, sd_bus_message *m
         r = sd_bus_message_read(message, "s", &name);
         if (r < 0)
                 return r;
-        if (!machine_name_is_valid(name))
+        if (!hostname_is_valid(name, 0))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid machine name");
 
         r = sd_bus_message_read_array(message, 'y', &v, &n);
diff --git a/src/machine/machined.c b/src/machine/machined.c
index 4d8891c4fc..6a5bf391e6 100644
--- a/src/machine/machined.c
+++ b/src/machine/machined.c
@@ -166,7 +166,7 @@ static int manager_enumerate_machines(Manager *m) {
                 if (startswith(de->d_name, "unit:"))
                         continue;
 
-                if (!machine_name_is_valid(de->d_name))
+                if (!hostname_is_valid(de->d_name, 0))
                         continue;
 
                 k = manager_add_machine(m, de->d_name, &machine);
diff --git a/src/network/generator/network-generator.c b/src/network/generator/network-generator.c
index 2fa21a067a..f9b51d8b7b 100644
--- a/src/network/generator/network-generator.c
+++ b/src/network/generator/network-generator.c
@@ -601,7 +601,7 @@ static int parse_cmdline_ip_address(Context *context, int family, const char *va
 
         if (p != value) {
                 hostname = strndupa(value, p - value);
-                if (!hostname_is_valid(hostname, false))
+                if (!hostname_is_valid(hostname, 0))
                         return -EINVAL;
         }
 
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 7ad8d087f4..73c3788e27 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -922,7 +922,7 @@ int config_parse_hostname(
         if (r < 0)
                 return r;
 
-        if (!hostname_is_valid(hn, false)) {
+        if (!hostname_is_valid(hn, 0)) {
                 log_syntax(unit, LOG_WARNING, filename, line, 0,
                            "Hostname is not valid, ignoring assignment: %s", rvalue);
                 return 0;
diff --git a/src/nspawn/nspawn-oci.c b/src/nspawn/nspawn-oci.c
index ca708be755..ccbae616ca 100644
--- a/src/nspawn/nspawn-oci.c
+++ b/src/nspawn/nspawn-oci.c
@@ -462,7 +462,7 @@ static int oci_hostname(const char *name, JsonVariant *v, JsonDispatchFlags flag
 
         assert_se(n = json_variant_string(v));
 
-        if (!hostname_is_valid(n, false))
+        if (!hostname_is_valid(n, 0))
                 return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL),
                                 "Hostname string is not a valid hostname: %s", n);
 
diff --git a/src/nspawn/nspawn-settings.c b/src/nspawn/nspawn-settings.c
index 92bb5120ab..b43d61468e 100644
--- a/src/nspawn/nspawn-settings.c
+++ b/src/nspawn/nspawn-settings.c
@@ -701,7 +701,7 @@ int config_parse_hostname(
         assert(rvalue);
         assert(s);
 
-        if (!hostname_is_valid(rvalue, false)) {
+        if (!hostname_is_valid(rvalue, 0)) {
                 log_syntax(unit, LOG_WARNING, filename, line, 0, "Invalid hostname, ignoring: %s", rvalue);
                 return 0;
         }
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 5e3d11be36..cfbc8f11bf 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -985,7 +985,7 @@ static int parse_argv(int argc, char *argv[]) {
                         if (isempty(optarg))
                                 arg_machine = mfree(arg_machine);
                         else {
-                                if (!machine_name_is_valid(optarg))
+                                if (!hostname_is_valid(optarg, 0))
                                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                                "Invalid machine name: %s", optarg);
 
@@ -999,7 +999,7 @@ static int parse_argv(int argc, char *argv[]) {
                         if (isempty(optarg))
                                 arg_hostname = mfree(arg_hostname);
                         else {
-                                if (!hostname_is_valid(optarg, false))
+                                if (!hostname_is_valid(optarg, 0))
                                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                                "Invalid hostname: %s", optarg);
 
@@ -2984,7 +2984,7 @@ static int determine_names(void) {
                         return log_oom();
 
                 hostname_cleanup(arg_machine);
-                if (!machine_name_is_valid(arg_machine))
+                if (!hostname_is_valid(arg_machine, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine machine name automatically, please use -M.");
 
                 if (arg_ephemeral) {
diff --git a/src/test/test-hostname-util.c b/src/test/test-hostname-util.c
index 73839b3115..c7a63bd047 100644
--- a/src/test/test-hostname-util.c
+++ b/src/test/test-hostname-util.c
@@ -10,40 +10,40 @@
 #include "util.h"
 
 static void test_hostname_is_valid(void) {
-        assert_se(hostname_is_valid("foobar", false));
-        assert_se(hostname_is_valid("foobar.com", false));
-        assert_se(!hostname_is_valid("foobar.com.", false));
-        assert_se(hostname_is_valid("fooBAR", false));
-        assert_se(hostname_is_valid("fooBAR.com", false));
-        assert_se(!hostname_is_valid("fooBAR.", false));
-        assert_se(!hostname_is_valid("fooBAR.com.", false));
-        assert_se(!hostname_is_valid("fööbar", false));
-        assert_se(!hostname_is_valid("", false));
-        assert_se(!hostname_is_valid(".", false));
-        assert_se(!hostname_is_valid("..", false));
-        assert_se(!hostname_is_valid("foobar.", false));
-        assert_se(!hostname_is_valid(".foobar", false));
-        assert_se(!hostname_is_valid("foo..bar", false));
-        assert_se(!hostname_is_valid("foo.bar..", false));
-        assert_se(!hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", false));
-        assert_se(!hostname_is_valid("au-xph5-rvgrdsb5hcxc-47et3a5vvkrc-server-wyoz4elpdpe3.openstack.local", false));
+        assert_se(hostname_is_valid("foobar", 0));
+        assert_se(hostname_is_valid("foobar.com", 0));
+        assert_se(!hostname_is_valid("foobar.com.", 0));
+        assert_se(hostname_is_valid("fooBAR", 0));
+        assert_se(hostname_is_valid("fooBAR.com", 0));
+        assert_se(!hostname_is_valid("fooBAR.", 0));
+        assert_se(!hostname_is_valid("fooBAR.com.", 0));
+        assert_se(!hostname_is_valid("fööbar", 0));
+        assert_se(!hostname_is_valid("", 0));
+        assert_se(!hostname_is_valid(".", 0));
+        assert_se(!hostname_is_valid("..", 0));
+        assert_se(!hostname_is_valid("foobar.", 0));
+        assert_se(!hostname_is_valid(".foobar", 0));
+        assert_se(!hostname_is_valid("foo..bar", 0));
+        assert_se(!hostname_is_valid("foo.bar..", 0));
+        assert_se(!hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", 0));
+        assert_se(!hostname_is_valid("au-xph5-rvgrdsb5hcxc-47et3a5vvkrc-server-wyoz4elpdpe3.openstack.local", 0));
 
-        assert_se(hostname_is_valid("foobar", true));
-        assert_se(hostname_is_valid("foobar.com", true));
-        assert_se(hostname_is_valid("foobar.com.", true));
-        assert_se(hostname_is_valid("fooBAR", true));
-        assert_se(hostname_is_valid("fooBAR.com", true));
-        assert_se(!hostname_is_valid("fooBAR.", true));
-        assert_se(hostname_is_valid("fooBAR.com.", true));
-        assert_se(!hostname_is_valid("fööbar", true));
-        assert_se(!hostname_is_valid("", true));
-        assert_se(!hostname_is_valid(".", true));
-        assert_se(!hostname_is_valid("..", true));
-        assert_se(!hostname_is_valid("foobar.", true));
-        assert_se(!hostname_is_valid(".foobar", true));
-        assert_se(!hostname_is_valid("foo..bar", true));
-        assert_se(!hostname_is_valid("foo.bar..", true));
-        assert_se(!hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", true));
+        assert_se(hostname_is_valid("foobar", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(hostname_is_valid("foobar.com", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(hostname_is_valid("foobar.com.", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(hostname_is_valid("fooBAR", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(hostname_is_valid("fooBAR.com", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("fooBAR.", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(hostname_is_valid("fooBAR.com.", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("fööbar", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid(".", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("..", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("foobar.", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid(".foobar", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("foo..bar", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("foo.bar..", VALID_HOSTNAME_TRAILING_DOT));
+        assert_se(!hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", VALID_HOSTNAME_TRAILING_DOT));
 }
 
 static void test_hostname_cleanup(void) {
@@ -151,7 +151,7 @@ static void test_hostname_malloc(void) {
 }
 
 static void test_fallback_hostname(void) {
-        if (!hostname_is_valid(FALLBACK_HOSTNAME, false)) {
+        if (!hostname_is_valid(FALLBACK_HOSTNAME, 0)) {
                 log_error("Configured fallback hostname \"%s\" is not valid.", FALLBACK_HOSTNAME);
                 exit(EXIT_FAILURE);
         }