diff --git a/include/proto/proto_tcp.h b/include/proto/proto_tcp.h
index d4e09c7..76f89b1 100644
--- a/include/proto/proto_tcp.h
+++ b/include/proto/proto_tcp.h
@@ -29,7 +29,7 @@
 
 int tcp_bind_socket(int fd, int flags, struct sockaddr_storage *local, struct sockaddr_storage *remote);
 int tcp_pause_listener(struct listener *l);
-int tcp_connect_server(struct connection *conn, int data, int delack);
+int tcp_connect_server(struct connection *conn, int flags);
 int tcp_connect_probe(struct connection *conn);
 int tcp_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir);
 int tcp_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir);
diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index 3cccc8f..8a4b77a 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -489,7 +489,8 @@
 		return SF_ERR_INTERNAL;
 
 	if (!conn_ctrl_ready(conn) || !conn_xprt_ready(conn)) {
-		ret = conn->ctrl->connect(conn, !channel_is_empty(si_oc(si)), 0);
+		ret = conn->ctrl->connect(conn, channel_is_empty(si_oc(si)) ?
+		                          CONNECT_HAS_DATA : 0);
 		if (ret != SF_ERR_NONE)
 			return ret;
 
diff --git a/include/types/protocol.h b/include/types/protocol.h
index 378e2b0..a33d129 100644
--- a/include/types/protocol.h
+++ b/include/types/protocol.h
@@ -73,7 +73,7 @@
 	int (*unbind_all)(struct protocol *proto);	/* unbind all bound listeners */
 	int (*enable_all)(struct protocol *proto);	/* enable all bound listeners */
 	int (*disable_all)(struct protocol *proto);	/* disable all bound listeners */
-	int (*connect)(struct connection *, int data, int delack);  /* connect function if any */
+	int (*connect)(struct connection *, int flags); /* connect function if any, see below for flags values */
 	int (*get_src)(int fd, struct sockaddr *, socklen_t, int dir); /* syscall used to retrieve src addr */
 	int (*get_dst)(int fd, struct sockaddr *, socklen_t, int dir); /* syscall used to retrieve dst addr */
 	int (*drain)(int fd);                           /* indicates whether we can safely close the fd */
@@ -85,6 +85,9 @@
 	struct list list;				/* list of registered protocols */
 };
 
+#define CONNECT_HAS_DATA                        0x00000001 /* There's data available to be sent */
+#define CONNECT_DELACK_SMART_CONNECT            0x00000002 /* Use a delayed ACK if the backend has tcp-smart-connect */
+#define CONNECT_DELACK_ALWAYS                   0x00000004 /* Use a delayed ACK */
 #endif /* _TYPES_PROTOCOL_H */
 
 /*
diff --git a/src/checks.c b/src/checks.c
index aeb3b79..a7b4b2f 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -1545,7 +1545,7 @@
 	struct protocol *proto;
 	struct tcpcheck_rule *tcp_rule = NULL;
 	int ret;
-	int quickack;
+	int connflags = 0;
 
 	/* we cannot have a connection here */
 	if (conn)
@@ -1637,14 +1637,15 @@
 	cs_attach(cs, check, &check_conn_cb);
 
 	/* only plain tcp-check supports quick ACK */
-	quickack = check->type == 0 || check->type == PR_O2_TCPCHK_CHK;
-
-	if (tcp_rule && tcp_rule->action == TCPCHK_ACT_EXPECT)
-		quickack = 0;
+	if (check->type != 0)
+		connflags |= CONNECT_HAS_DATA;
+	if ((check->type == 0 || check->type == PR_O2_TCPCHK_CHK) &&
+	    (!tcp_rule || tcp_rule->action != TCPCHK_ACT_EXPECT))
+		connflags |= CONNECT_DELACK_ALWAYS;
 
 	ret = SF_ERR_INTERNAL;
 	if (proto && proto->connect)
-		ret = proto->connect(conn, check->type, quickack ? 2 : 0);
+		ret = proto->connect(conn, connflags);
 
 
 #ifdef USE_OPENSSL
@@ -2845,8 +2846,7 @@
 			ret = SF_ERR_INTERNAL;
 			if (proto && proto->connect)
 				ret = proto->connect(conn,
-						     1 /* I/O polling is always needed */,
-						     (next && next->action == TCPCHK_ACT_EXPECT) ? 0 : 2);
+						     CONNECT_HAS_DATA /* I/O polling is always needed */ | (next && next->action == TCPCHK_ACT_EXPECT) ? 0 : CONNECT_DELACK_ALWAYS);
 			if (check->current_step->conn_opts & TCPCHK_OPT_SEND_PROXY) {
 				conn->send_proxy_ofs = 1;
 				conn->flags |= CO_FL_SEND_PROXY;
diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index 713da37..97a9348 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -49,7 +49,7 @@
 static void sockpair_add_listener(struct listener *listener, int port);
 static int sockpair_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static int sockpair_bind_listeners(struct protocol *proto, char *errmsg, int errlen);
-static int sockpair_connect_server(struct connection *conn, int data, int delack);
+static int sockpair_connect_server(struct connection *conn, int flags);
 
 /* Note: must not be declared <const> as its list will be overwritten */
 static struct protocol proto_sockpair = {
@@ -237,7 +237,7 @@
  * The connection's fd is inserted only when SF_ERR_NONE is returned, otherwise
  * it's invalid and the caller has nothing to do.
  */
-static int sockpair_connect_server(struct connection *conn, int data, int delack)
+static int sockpair_connect_server(struct connection *conn, int flags)
 {
 	int sv[2], fd, dst_fd = -1;
 
@@ -289,7 +289,8 @@
 	}
 
 	/* if a send_proxy is there, there are data */
-	data |= conn->send_proxy_ofs;
+	if (conn->send_proxy_ofs)
+		flags |= CONNECT_HAS_DATA;
 
 	if (global.tune.server_sndbuf)
                 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &global.tune.server_sndbuf, sizeof(global.tune.server_sndbuf));
@@ -334,10 +335,10 @@
 		 * layer when the connection is already OK otherwise we'll have
 		 * no other opportunity to do it later (eg: health checks).
 		 */
-		data = 1;
+		flags |= CONNECT_HAS_DATA;
 	}
 
-	if (data)
+	if (flags & CONNECT_HAS_DATA)
 		conn_xprt_want_send(conn);  /* prepare to send data if any */
 
 	return SF_ERR_NONE;  /* connection is OK */
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index d4cad22..e668a85 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -266,11 +266,11 @@
  * depending on conn->target. Only OBJ_TYPE_PROXY and OBJ_TYPE_SERVER are
  * supported. The <data> parameter is a boolean indicating whether there are data
  * waiting for being sent or not, in order to adjust data write polling and on
- * some platforms, the ability to avoid an empty initial ACK. The <delack> argument
- * allows the caller to force using a delayed ACK when establishing the connection :
+ * some platforms, the ability to avoid an empty initial ACK. The <flags> argument
+ * allows the caller to force using a delayed ACK when establishing the connection
  *   - 0 = no delayed ACK unless data are advertised and backend has tcp-smart-connect
- *   - 1 = delayed ACK if backend has tcp-smart-connect, regardless of data
- *   - 2 = delayed ACK regardless of backend options
+ *   - CONNECT_DELACK_SMART_CONNECT = delayed ACK if backend has tcp-smart-connect, regardless of data
+ *   - CONNECT_DELACK_ALWAYS = delayed ACK regardless of backend options
  *
  * Note that a pending send_proxy message accounts for data.
  *
@@ -287,7 +287,7 @@
  * it's invalid and the caller has nothing to do.
  */
 
-int tcp_connect_server(struct connection *conn, int data, int delack)
+int tcp_connect_server(struct connection *conn, int flags)
 {
 	int fd;
 	struct server *srv;
@@ -481,7 +481,10 @@
 	 * machine with the first ACK. We only do this if there are pending
 	 * data in the buffer.
 	 */
-	if (delack == 2 || ((delack || data || conn->send_proxy_ofs) && (be->options2 & PR_O2_SMARTCON)))
+	if (flags & (CONNECT_DELACK_ALWAYS) ||
+	    ((flags & CONNECT_DELACK_SMART_CONNECT ||
+	      (flags & CONNECT_HAS_DATA) || conn->send_proxy_ofs) &&
+	     (be->options2 & PR_O2_SMARTCON)))
                 setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &zero, sizeof(zero));
 #endif
 
@@ -572,10 +575,10 @@
 		 * layer when the connection is already OK otherwise we'll have
 		 * no other opportunity to do it later (eg: health checks).
 		 */
-		data = 1;
+		flags |= CONNECT_HAS_DATA;
 	}
 
-	if (data)
+	if (flags & CONNECT_HAS_DATA)
 		conn_xprt_want_send(conn);  /* prepare to send data if any */
 
 	return SF_ERR_NONE;  /* connection is OK */
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
index 980a226..42e0dc8 100644
--- a/src/proto_uxst.c
+++ b/src/proto_uxst.c
@@ -48,7 +48,7 @@
 static int uxst_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static int uxst_bind_listeners(struct protocol *proto, char *errmsg, int errlen);
 static int uxst_unbind_listeners(struct protocol *proto);
-static int uxst_connect_server(struct connection *conn, int data, int delack);
+static int uxst_connect_server(struct connection *conn, int flags);
 static void uxst_add_listener(struct listener *listener, int port);
 static int uxst_pause_listener(struct listener *l);
 static int uxst_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir);
@@ -430,7 +430,7 @@
  * The connection's fd is inserted only when SF_ERR_NONE is returned, otherwise
  * it's invalid and the caller has nothing to do.
  */
-static int uxst_connect_server(struct connection *conn, int data, int delack)
+static int uxst_connect_server(struct connection *conn, int flags)
 {
 	int fd;
 	struct server *srv;
@@ -510,7 +510,8 @@
 	}
 
 	/* if a send_proxy is there, there are data */
-	data |= conn->send_proxy_ofs;
+	if (conn->send_proxy_ofs)
+		flags |= CONNECT_HAS_DATA;
 
 	if (global.tune.server_sndbuf)
                 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &global.tune.server_sndbuf, sizeof(global.tune.server_sndbuf));
@@ -585,10 +586,10 @@
 		 * layer when the connection is already OK otherwise we'll have
 		 * no other opportunity to do it later (eg: health checks).
 		 */
-		data = 1;
+		flags |= CONNECT_HAS_DATA;
 	}
 
-	if (data)
+	if (flags & CONNECT_HAS_DATA)
 		conn_xprt_want_send(conn);  /* prepare to send data if any */
 
 	return SF_ERR_NONE;  /* connection is OK */