diff --git a/src/include/ipxe/dhcpv6.h b/src/include/ipxe/dhcpv6.h
index 48cb76337..6e70f7e63 100644
--- a/src/include/ipxe/dhcpv6.h
+++ b/src/include/ipxe/dhcpv6.h
@@ -145,6 +145,21 @@ struct dhcpv6_user_class_option {
 /** DHCPv6 user class option */
 #define DHCPV6_USER_CLASS 15
 
+/** DHCPv6 vendor class option */
+#define DHCPV6_VENDOR_CLASS 16
+
+/** DHCPv6 PXE vendor class
+ *
+ * The DHCPv6 vendor class includes a field for an IANA enterprise
+ * number.  The EDK2 codebase uses the value 343, with the comment:
+ *
+ *     TODO: IANA TBD: temporarily using Intel's
+ *
+ * Since this "temporarily" has applied since at least 2010, we assume
+ * that it has become a de facto standard.
+ */
+#define DHCPV6_VENDOR_CLASS_PXE 343
+
 /** DHCPv6 DNS recursive name server option */
 #define DHCPV6_DNS_SERVERS 23
 
@@ -170,13 +185,22 @@ struct dhcpv6_user_class_option {
  */
 #define DHCPV6_LOG_SERVERS 0xffffffffUL
 
+/** Construct a DHCPv6 byte value */
+#define DHCPV6_BYTE_VALUE( value ) ( (value) & 0xff )
+
+/** Construct a DHCPv6 word value */
+#define DHCPV6_WORD_VALUE( value ) \
+	DHCPV6_BYTE_VALUE ( (value) >> 8 ), DHCPV6_BYTE_VALUE ( (value) >> 0 )
+
+/** Construct a DHCPv6 dword value */
+#define DHCPV6_DWORD_VALUE( value ) \
+	DHCPV6_WORD_VALUE ( (value) >> 16 ), DHCPV6_WORD_VALUE ( (value) >> 0 )
+
 /** Construct a DHCPv6 option code */
-#define DHCPV6_CODE( code ) \
-	( ( (code) >> 8 ) & 0xff ), ( ( (code) >> 0 ) & 0xff )
+#define DHCPV6_CODE( code ) DHCPV6_WORD_VALUE ( code )
 
 /** Construct a DHCPv6 option length */
-#define DHCPV6_LEN( len ) \
-	( ( (len) >> 8 ) & 0xff ), ( ( (len) >> 0 ) & 0xff )
+#define DHCPV6_LEN( len ) DHCPV6_WORD_VALUE ( len )
 
 /** Construct a DHCPv6 option from a list of bytes */
 #define DHCPV6_OPTION( ... ) \
@@ -186,16 +210,13 @@ struct dhcpv6_user_class_option {
 #define DHCPV6_STRING( ... ) DHCPV6_OPTION ( __VA_ARGS__ )
 
 /** Construct a byte-valued DHCPv6 option */
-#define DHCPV6_BYTE( value ) DHCPV6_OPTION ( value )
+#define DHCPV6_BYTE( value ) DHCPV6_OPTION ( DHCPV6_BYTE_VALUE ( value ) )
 
 /** Construct a word-valued DHCPv6 option */
-#define DHCPV6_WORD( value ) DHCPV6_OPTION ( ( ( (value) >> 8 ) & 0xff ), \
-					     ( ( (value) >> 0 ) & 0xff ) )
+#define DHCPV6_WORD( value ) DHCPV6_OPTION ( DHCPV6_WORD_VALUE ( value ) )
+
 /** Construct a dword-valued DHCPv6 option */
-#define DHCPV6_DWORD( value ) DHCPV6_OPTION ( ( ( (value) >> 24 ) & 0xff ), \
-					      ( ( (value) >> 16 ) & 0xff ), \
-					      ( ( (value) >>  8 ) & 0xff ), \
-					      ( ( (value) >>  0 ) & 0xff ) )
+#define DHCPV6_DWORD( value ) DHCPV6_OPTION ( DHCPV6_DWORD_VALUE ( value ) )
 
 /**
  * Any DHCPv6 option
diff --git a/src/net/udp/dhcpv6.c b/src/net/udp/dhcpv6.c
index 8b216e9a2..ef07f54e3 100644
--- a/src/net/udp/dhcpv6.c
+++ b/src/net/udp/dhcpv6.c
@@ -372,6 +372,9 @@ static uint8_t dhcpv6_request_options_data[] = {
 			DHCPV6_CODE ( DHCPV6_DOMAIN_LIST ),
 			DHCPV6_CODE ( DHCPV6_BOOTFILE_URL ),
 			DHCPV6_CODE ( DHCPV6_BOOTFILE_PARAM ) ),
+	DHCPV6_CODE ( DHCPV6_VENDOR_CLASS ),
+	DHCPV6_OPTION ( DHCPV6_DWORD_VALUE ( DHCPV6_VENDOR_CLASS_PXE ),
+			DHCPV6_STRING ( DHCP_ARCH_VENDOR_CLASS_ID ) ),
 	DHCPV6_CODE ( DHCPV6_CLIENT_ARCHITECTURE ),
 	DHCPV6_WORD ( DHCP_ARCH_CLIENT_ARCHITECTURE ),
 	DHCPV6_CODE ( DHCPV6_CLIENT_NDI ),