diff --git a/include/haproxy/protocol-t.h b/include/haproxy/protocol-t.h
index 494f95d03..0119cf2fb 100644
--- a/include/haproxy/protocol-t.h
+++ b/include/haproxy/protocol-t.h
@@ -83,7 +83,6 @@ struct protocol {
 	char name[PROTO_NAME_LEN];			/* protocol name, zero-terminated */
 	struct proto_fam *fam;                          /* protocol family */
 	int ctrl_type;                                  /* control layer type (SOCK_STREAM/SOCK_DGRAM) */
-	int sock_domain;				/* socket domain, as passed to socket()   */
 	int sock_type;					/* socket type, as passed to socket()     */
 	int sock_prot;					/* socket protocol, as passed to socket() */
 
diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index fe74ff469..2f691f7ec 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -67,7 +67,6 @@ static struct protocol proto_sockpair = {
 	.name = "sockpair",
 	.fam = &proto_fam_sockpair,
 	.ctrl_type = SOCK_STREAM,
-	.sock_domain = AF_CUST_SOCKPAIR,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = 0,
 	.add = default_add_listener,
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 30a0045be..eecb299e6 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -55,7 +55,6 @@ static struct protocol proto_tcpv4 = {
 	.name = "tcpv4",
 	.fam = &proto_fam_inet4,
 	.ctrl_type = SOCK_STREAM,
-	.sock_domain = AF_INET,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = IPPROTO_TCP,
 	.add = default_add_listener,
@@ -85,7 +84,6 @@ static struct protocol proto_tcpv6 = {
 	.name = "tcpv6",
 	.fam = &proto_fam_inet6,
 	.ctrl_type = SOCK_STREAM,
-	.sock_domain = AF_INET6,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = IPPROTO_TCP,
 	.add = default_add_listener,
diff --git a/src/proto_udp.c b/src/proto_udp.c
index 5ac7b1588..12e25afdf 100644
--- a/src/proto_udp.c
+++ b/src/proto_udp.c
@@ -51,7 +51,6 @@ static struct protocol proto_udp4 = {
 	.name = "udp4",
 	.fam = &proto_fam_inet4,
 	.ctrl_type = SOCK_DGRAM,
-	.sock_domain = AF_INET,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.add = default_add_listener,
@@ -77,7 +76,6 @@ static struct protocol proto_udp6 = {
 	.name = "udp6",
 	.fam = &proto_fam_inet6,
 	.ctrl_type = SOCK_DGRAM,
-	.sock_domain = AF_INET6,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
 	.add = default_add_listener,
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
index 9c19374f7..52e90ae4a 100644
--- a/src/proto_uxst.c
+++ b/src/proto_uxst.c
@@ -51,7 +51,6 @@ static struct protocol proto_unix = {
 	.name = "unix_stream",
 	.fam = &proto_fam_unix,
 	.ctrl_type = SOCK_STREAM,
-	.sock_domain = PF_UNIX,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = 0,
 	.add = default_add_listener,
diff --git a/src/protocol.c b/src/protocol.c
index 8ea36cb81..cb9f6e7c1 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -37,8 +37,8 @@ void protocol_register(struct protocol *proto)
 {
 	HA_SPIN_LOCK(PROTO_LOCK, &proto_lock);
 	LIST_ADDQ(&protocols, &proto->list);
-	if (proto->sock_domain >= 0 && proto->sock_domain < AF_CUST_MAX)
-		__protocol_by_family[proto->sock_domain]
+	if (proto->fam->sock_domain >= 0 && proto->fam->sock_domain < AF_CUST_MAX)
+		__protocol_by_family[proto->fam->sock_domain]
 			[proto->sock_type == SOCK_DGRAM]
 			[proto->ctrl_type == SOCK_DGRAM] = proto;
 	HA_SPIN_UNLOCK(PROTO_LOCK, &proto_lock);