diff --git a/include/haproxy/protocol-t.h b/include/haproxy/protocol-t.h
index f74a2e1a6..2c5b66227 100644
--- a/include/haproxy/protocol-t.h
+++ b/include/haproxy/protocol-t.h
@@ -39,9 +39,7 @@ struct connection;
  */
 #define AF_CUST_EXISTING_FD  (AF_MAX + 1)
 #define AF_CUST_SOCKPAIR     (AF_MAX + 2)
-#define AF_CUST_UDP4         (AF_MAX + 3)
-#define AF_CUST_UDP6         (AF_MAX + 4)
-#define AF_CUST_MAX          (AF_MAX + 5)
+#define AF_CUST_MAX          (AF_MAX + 3)
 
 /*
  * Test in case AF_CUST_MAX overflows the sa_family_t (unsigned int)
diff --git a/src/proto_udp.c b/src/proto_udp.c
index 74408b4ec..2333b5d9e 100644
--- a/src/proto_udp.c
+++ b/src/proto_udp.c
@@ -1,5 +1,5 @@
 /*
- * AF_CUST_UDP/AF_CUST_UDP6 UDP protocol layer
+ * UDP protocol layer on top of AF_INET/AF_INET6
  *
  * Copyright 2019 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
  *
@@ -49,7 +49,7 @@ static struct protocol proto_udp4 = {
 	.name = "udp4",
 	.fam = &proto_fam_inet4,
 	.ctrl_type = SOCK_DGRAM,
-	.sock_domain = AF_CUST_UDP4,
+	.sock_domain = AF_INET,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.accept = NULL,
@@ -69,7 +69,7 @@ static struct protocol proto_udp6 = {
 	.name = "udp6",
 	.fam = &proto_fam_inet6,
 	.ctrl_type = SOCK_DGRAM,
-	.sock_domain = AF_CUST_UDP6,
+	.sock_domain = AF_INET6,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.accept = NULL,