diff --git a/src/libsystemd-network/dhcp-identifier.c b/src/libsystemd-network/dhcp-identifier.c
index c01c1cf6d6..d0610a32e2 100644
--- a/src/libsystemd-network/dhcp-identifier.c
+++ b/src/libsystemd-network/dhcp-identifier.c
@@ -15,7 +15,6 @@
 #include "udev-util.h"
 #include "virt.h"
 
-#define SYSTEMD_PEN    43793
 #define HASH_KEY       SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
 #define APPLICATION_ID SD_ID128_MAKE(a5,0a,d1,12,bf,60,45,77,a2,fb,74,1a,b1,95,5b,03)
 #define USEC_2000       ((usec_t) 946684800000000) /* 2000-01-01 00:00:00 UTC */
diff --git a/src/libsystemd-network/dhcp-identifier.h b/src/libsystemd-network/dhcp-identifier.h
index b3115125d9..76abd6583e 100644
--- a/src/libsystemd-network/dhcp-identifier.h
+++ b/src/libsystemd-network/dhcp-identifier.h
@@ -8,6 +8,8 @@
 #include "time-util.h"
 #include "unaligned.h"
 
+#define SYSTEMD_PEN    43793
+
 typedef enum DUIDType {
         DUID_TYPE_LLT       = 1,
         DUID_TYPE_EN        = 2,
diff --git a/src/libsystemd-network/dhcp6-internal.h b/src/libsystemd-network/dhcp6-internal.h
index 8b651636ca..ced85fd3af 100644
--- a/src/libsystemd-network/dhcp6-internal.h
+++ b/src/libsystemd-network/dhcp6-internal.h
@@ -98,6 +98,7 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, const DHCP6IA *ia);
 int dhcp6_option_append_pd(uint8_t *buf, size_t len, const DHCP6IA *pd, DHCP6Address *hint_pd_prefix);
 int dhcp6_option_append_fqdn(uint8_t **buf, size_t *buflen, const char *fqdn);
 int dhcp6_option_append_user_class(uint8_t **buf, size_t *buflen, char **user_class);
+int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *buflen, char **user_class);
 int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode,
                        size_t *optlen, uint8_t **optvalue);
 int dhcp6_option_parse_status(DHCP6Option *option, size_t len);
diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index d1a02da35f..0ec36507cd 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -9,6 +9,7 @@
 #include "sd-dhcp6-client.h"
 
 #include "alloc-util.h"
+#include "dhcp-identifier.h"
 #include "dhcp6-internal.h"
 #include "dhcp6-lease-internal.h"
 #include "dhcp6-protocol.h"
@@ -180,7 +181,6 @@ int dhcp6_option_append_user_class(uint8_t **buf, size_t *buflen, char **user_cl
 
                 if (len > 0xffff)
                         return -ENAMETOOLONG;
-
                 q = realloc(p, total + len + 2);
                 if (!q)
                         return -ENOMEM;
@@ -197,6 +197,46 @@ int dhcp6_option_append_user_class(uint8_t **buf, size_t *buflen, char **user_cl
         return dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_USER_CLASS, total, p);
 }
 
+int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *buflen, char **vendor_class) {
+        _cleanup_free_ uint8_t *p = NULL;
+        uint32_t enterprise_identifier;
+        size_t total, offset;
+        char **s;
+
+        assert(buf);
+        assert(*buf);
+        assert(buflen);
+        assert(vendor_class);
+
+        enterprise_identifier = htobe32(SYSTEMD_PEN);
+
+        p = memdup(&enterprise_identifier, sizeof(enterprise_identifier));
+        if (!p)
+                return -ENOMEM;
+
+        total = sizeof(enterprise_identifier);
+        offset = total;
+
+        STRV_FOREACH(s, vendor_class) {
+                size_t len = strlen(*s);
+                uint8_t *q;
+
+                q = realloc(p, total + len + 2);
+                if (!q)
+                        return -ENOMEM;
+
+                p = q;
+
+                unaligned_write_be16(&p[offset], len);
+                memcpy(&p[offset + 2], *s, len);
+
+                offset += 2 + len;
+                total += 2 + len;
+        }
+
+        return dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_VENDOR_CLASS, total, p);
+}
+
 int dhcp6_option_append_pd(uint8_t *buf, size_t len, const DHCP6IA *pd, DHCP6Address *hint_pd_prefix) {
         DHCP6Option *option = (DHCP6Option *)buf;
         size_t i = sizeof(*option) + sizeof(pd->ia_pd);
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 0240f1b7c7..ce9e6cae7e 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -68,6 +68,7 @@ struct sd_dhcp6_client {
         char *fqdn;
         char *mudurl;
         char **user_class;
+        char **vendor_class;
         sd_event_source *receive_message;
         usec_t retransmit_time;
         uint8_t retransmit_count;
@@ -380,7 +381,7 @@ int sd_dhcp6_client_set_request_mud_url(sd_dhcp6_client *client, const char *mud
         assert_return(client, -EINVAL);
         assert_return(client->state == DHCP6_STATE_STOPPED, -EBUSY);
         assert_return(mudurl, -EINVAL);
-        assert_return(strlen(mudurl) <= 255, -EINVAL);
+        assert_return(strlen(mudurl) <= UINT8_MAX, -EINVAL);
         assert_return(http_url_is_valid(mudurl), -EINVAL);
 
         return free_and_strdup(&client->mudurl, mudurl);
@@ -392,6 +393,7 @@ int sd_dhcp6_client_set_request_user_class(sd_dhcp6_client *client, char **user_
 
         assert_return(client, -EINVAL);
         assert_return(client->state == DHCP6_STATE_STOPPED, -EBUSY);
+
         assert_return(user_class, -EINVAL);
 
         STRV_FOREACH(p, user_class)
@@ -407,6 +409,27 @@ int sd_dhcp6_client_set_request_user_class(sd_dhcp6_client *client, char **user_
         return 0;
 }
 
+int sd_dhcp6_client_set_request_vendor_class(sd_dhcp6_client *client, char **vendor_class) {
+        _cleanup_strv_free_ char **s = NULL;
+        char **p;
+
+        assert_return(client, -EINVAL);
+        assert_return(client->state == DHCP6_STATE_STOPPED, -EBUSY);
+        assert_return(vendor_class, -EINVAL);
+
+        STRV_FOREACH(p, vendor_class)
+                if (strlen(*p) > UINT8_MAX)
+                        return -ENAMETOOLONG;
+
+        s = strv_copy(vendor_class);
+        if (!s)
+                return -ENOMEM;
+
+        client->vendor_class = TAKE_PTR(s);
+
+        return 0;
+}
+
 int sd_dhcp6_client_get_prefix_delegation(sd_dhcp6_client *client, int *delegation) {
         assert_return(client, -EINVAL);
         assert_return(delegation, -EINVAL);
@@ -593,6 +616,12 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (client->vendor_class) {
+                        r = dhcp6_option_append_vendor_class(&opt, &optlen, client->vendor_class);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->ia_pd, &client->hint_pd_prefix);
                         if (r < 0)
@@ -645,6 +674,12 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (client->vendor_class) {
+                        r = dhcp6_option_append_vendor_class(&opt, &optlen, client->vendor_class);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd, NULL);
                         if (r < 0)
@@ -685,6 +720,12 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {
                                 return r;
                 }
 
+                if (client->vendor_class) {
+                        r = dhcp6_option_append_vendor_class(&opt, &optlen, client->vendor_class);
+                        if (r < 0)
+                                return r;
+                }
+
                 if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) {
                         r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd, NULL);
                         if (r < 0)
@@ -1645,6 +1686,7 @@ static sd_dhcp6_client *dhcp6_client_free(sd_dhcp6_client *client) {
 
         ordered_hashmap_free(client->extra_options);
         strv_free(client->user_class);
+        strv_free(client->vendor_class);
 
         return mfree(client);
 }
diff --git a/src/systemd/sd-dhcp6-client.h b/src/systemd/sd-dhcp6-client.h
index 8011457b76..c342be4b29 100644
--- a/src/systemd/sd-dhcp6-client.h
+++ b/src/systemd/sd-dhcp6-client.h
@@ -125,10 +125,12 @@ int sd_dhcp6_client_set_request_option(
 int sd_dhcp6_client_set_request_mud_url(
                 sd_dhcp6_client *client,
                 const char *mudurl);
-
 int sd_dhcp6_client_set_request_user_class(
                 sd_dhcp6_client *client,
                 char** user_class);
+int sd_dhcp6_client_set_request_vendor_class(
+                sd_dhcp6_client *client,
+                char** vendor_class);
 int sd_dhcp6_client_set_prefix_delegation_hint(
                 sd_dhcp6_client *client,
                 uint8_t prefixlen,