diff --git a/include/types/checks.h b/include/types/checks.h
index 4b35d30..3abebe1 100644
--- a/include/types/checks.h
+++ b/include/types/checks.h
@@ -180,7 +180,6 @@
 	char **argv;				/* the arguments to use if running a process-based check */
 	char **envp;				/* the environment to use if running a process-based check */
 	struct pid_list *curpid;		/* entry in pid_list used for current process-based test, or -1 if not in test */
-	struct protocol *proto;	        	/* server address protocol for health checks */
 	struct sockaddr_storage addr;   	/* the address to check */
 };
 
diff --git a/include/types/server.h b/include/types/server.h
index 23bb2b7..f987e25 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -196,7 +196,6 @@
 	const struct netns_entry *netns;        /* contains network namespace name or NULL. Network namespace comes from configuration */
 	/* warning, these structs are huge, keep them at the bottom */
 	struct sockaddr_storage addr;		/* the address to connect to */
-	struct protocol *proto;	                /* server address protocol */
 	struct xprt_ops *xprt;                  /* transport-layer operations */
 	unsigned down_time;			/* total time the server was down */
 	time_t last_change;			/* last time, when the state was changed */
diff --git a/src/backend.c b/src/backend.c
index 721c12a..dbc6d06 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1059,7 +1059,7 @@
 
 		/* set the correct protocol on the output stream interface */
 		if (objt_server(s->target)) {
-			conn_prepare(srv_conn, objt_server(s->target)->proto, objt_server(s->target)->xprt);
+			conn_prepare(srv_conn, protocol_by_family(srv_conn->addr.to.ss_family), objt_server(s->target)->xprt);
 		}
 		else if (obj_type(s->target) == OBJ_TYPE_PROXY) {
 			/* proxies exclusively run on raw_sock right now */
diff --git a/src/checks.c b/src/checks.c
index 62a0721..8a9eab5 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -1440,29 +1440,29 @@
 
 	/* prepare a new connection */
 	conn_init(conn);
-	conn_prepare(conn, check->proto, check->xprt);
-	conn_attach(conn, check, &check_conn_cb);
-	conn->target = &s->obj_type;
-
-	/* no client address */
-	clear_addr(&conn->addr.from);
 
 	if (is_addr(&check->addr)) {
-
 		/* we'll connect to the check addr specified on the server */
 		conn->addr.to = check->addr;
-		proto = check->proto;
 	}
 	else {
 		/* we'll connect to the addr on the server */
 		conn->addr.to = s->addr;
-		proto = s->proto;
 	}
 
 	if (check->port) {
 		set_host_port(&conn->addr.to, check->port);
 	}
 
+	proto = protocol_by_family(conn->addr.to.ss_family);
+
+	conn_prepare(conn, proto, check->xprt);
+	conn_attach(conn, check, &check_conn_cb);
+	conn->target = &s->obj_type;
+
+	/* no client address */
+	clear_addr(&conn->addr.from);
+
 	/* only plain tcp-check supports quick ACK */
 	quickack = check->type == 0 || check->type == PR_O2_TCPCHK_CHK;
 
@@ -2504,13 +2504,12 @@
 			if (is_addr(&check->addr)) {
 				/* we'll connect to the check addr specified on the server */
 				conn->addr.to = check->addr;
-				proto = check->proto;
 			}
 			else {
 				/* we'll connect to the addr on the server */
 				conn->addr.to = s->addr;
-				proto = s->proto;
 			}
+			proto = protocol_by_family(conn->addr.to.ss_family);
 
 			/* port */
 			if (check->current_step->port)
@@ -2908,7 +2907,6 @@
 		if (!get_host_port(&mailer->addr))
 			/* Default to submission port */
 			check->port = 587;
-		check->proto = mailer->proto;
 		check->addr = mailer->addr;
 		check->server = s;
 	}
diff --git a/src/server.c b/src/server.c
index 118a1ed..edd7670 100644
--- a/src/server.c
+++ b/src/server.c
@@ -904,10 +904,9 @@
 			}
 
 			newsrv->addr = *sk;
-			newsrv->proto = newsrv->check.proto = newsrv->agent.proto = protocol_by_family(newsrv->addr.ss_family);
 			newsrv->xprt  = newsrv->check.xprt = newsrv->agent.xprt = &raw_sock;
 
-			if (!newsrv->proto) {
+			if (!protocol_by_family(newsrv->addr.ss_family)) {
 				Alert("parsing [%s:%d] : Unknown protocol family %d '%s'\n",
 				      file, linenum, newsrv->addr.ss_family, args[2]);
 				err_code |= ERR_ALERT | ERR_FATAL;
@@ -1114,7 +1113,6 @@
 				}
 
 				newsrv->check.addr = newsrv->agent.addr = *sk;
-				newsrv->check.proto = newsrv->agent.proto = protocol_by_family(sk->ss_family);
 				cur_arg += 2;
 			}
 			else if (!strcmp(args[cur_arg], "port")) {