Index: uspace/srv/net/tcp/conn.c
===================================================================
--- uspace/srv/net/tcp/conn.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/conn.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -84,7 +84,7 @@
 
 /** Initialize connections. */
-int tcp_conns_init(void)
-{
-	int rc;
+errno_t tcp_conns_init(void)
+{
+	errno_t rc;
 
 	rc = amap_create(&amap);
@@ -303,8 +303,8 @@
  * Add connection to the connection map.
  */
-int tcp_conn_add(tcp_conn_t *conn)
+errno_t tcp_conn_add(tcp_conn_t *conn)
 {
 	inet_ep2_t aepp;
-	int rc;
+	errno_t rc;
 
 	tcp_conn_addref(conn);
@@ -425,5 +425,5 @@
 tcp_conn_t *tcp_conn_find_ref(inet_ep2_t *epp)
 {
-	int rc;
+	errno_t rc;
 	void *arg;
 	tcp_conn_t *conn;
@@ -1242,5 +1242,5 @@
 	inet_ep2_t aepp;
 	inet_ep2_t oldepp;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: tcp_conn_segment_arrived(%p)",
Index: uspace/srv/net/tcp/conn.h
===================================================================
--- uspace/srv/net/tcp/conn.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/conn.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -40,9 +40,9 @@
 #include "tcp_type.h"
 
-extern int tcp_conns_init(void);
+extern errno_t tcp_conns_init(void);
 extern void tcp_conns_fini(void);
 extern tcp_conn_t *tcp_conn_new(inet_ep2_t *);
 extern void tcp_conn_delete(tcp_conn_t *);
-extern int tcp_conn_add(tcp_conn_t *);
+extern errno_t tcp_conn_add(tcp_conn_t *);
 extern void tcp_conn_reset(tcp_conn_t *conn);
 extern void tcp_conn_sync(tcp_conn_t *);
Index: uspace/srv/net/tcp/inet.c
===================================================================
--- uspace/srv/net/tcp/inet.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/inet.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -50,5 +50,5 @@
 #define NAME       "tcp"
 
-static int tcp_inet_ev_recv(inet_dgram_t *dgram);
+static errno_t tcp_inet_ev_recv(inet_dgram_t *dgram);
 static void tcp_received_pdu(tcp_pdu_t *pdu);
 
@@ -58,5 +58,5 @@
 
 /** Received datagram callback */
-static int tcp_inet_ev_recv(inet_dgram_t *dgram)
+static errno_t tcp_inet_ev_recv(inet_dgram_t *dgram)
 {
 	uint8_t *pdu_raw;
@@ -121,5 +121,5 @@
 void tcp_transmit_pdu(tcp_pdu_t *pdu)
 {
-	int rc;
+	errno_t rc;
 	uint8_t *pdu_raw;
 	size_t pdu_raw_size;
@@ -169,7 +169,7 @@
 
 /** Initialize TCP inet interface. */
-int tcp_inet_init(void)
+errno_t tcp_inet_init(void)
 {
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_inet_init()");
Index: uspace/srv/net/tcp/inet.h
===================================================================
--- uspace/srv/net/tcp/inet.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/inet.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -38,5 +38,5 @@
 #include "tcp_type.h"
 
-extern int tcp_inet_init(void);
+extern errno_t tcp_inet_init(void);
 extern void tcp_transmit_pdu(tcp_pdu_t *);
 
Index: uspace/srv/net/tcp/iqueue.c
===================================================================
--- uspace/srv/net/tcp/iqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/iqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -137,5 +137,5 @@
  * @return		EOK on success, ENOENT if no segment is ready
  */
-int tcp_iqueue_get_ready_seg(tcp_iqueue_t *iqueue, tcp_segment_t **seg)
+errno_t tcp_iqueue_get_ready_seg(tcp_iqueue_t *iqueue, tcp_segment_t **seg)
 {
 	tcp_iqueue_entry_t *iqe;
Index: uspace/srv/net/tcp/iqueue.h
===================================================================
--- uspace/srv/net/tcp/iqueue.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/iqueue.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -41,5 +41,5 @@
 extern void tcp_iqueue_insert_seg(tcp_iqueue_t *, tcp_segment_t *);
 extern void tcp_iqueue_remove_seg(tcp_iqueue_t *, tcp_segment_t *);
-extern int tcp_iqueue_get_ready_seg(tcp_iqueue_t *, tcp_segment_t **);
+extern errno_t tcp_iqueue_get_ready_seg(tcp_iqueue_t *, tcp_segment_t **);
 
 #endif
Index: uspace/srv/net/tcp/ncsim.c
===================================================================
--- uspace/srv/net/tcp/ncsim.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/ncsim.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -123,10 +123,10 @@
 
 /** Network condition simulator handler fibril. */
-static int tcp_ncsim_fibril(void *arg)
+static errno_t tcp_ncsim_fibril(void *arg)
 {
 	link_t *link;
 	tcp_squeue_entry_t *sqe;
 	inet_ep2_t rident;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ncsim_fibril()");
Index: uspace/srv/net/tcp/pdu.c
===================================================================
--- uspace/srv/net/tcp/pdu.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/pdu.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -191,5 +191,5 @@
 }
 
-static int tcp_header_encode(inet_ep2_t *epp, tcp_segment_t *seg,
+static errno_t tcp_header_encode(inet_ep2_t *epp, tcp_segment_t *seg,
     void **header, size_t *size)
 {
@@ -295,5 +295,5 @@
 
 /** Decode incoming PDU */
-int tcp_pdu_decode(tcp_pdu_t *pdu, inet_ep2_t *epp, tcp_segment_t **seg)
+errno_t tcp_pdu_decode(tcp_pdu_t *pdu, inet_ep2_t *epp, tcp_segment_t **seg)
 {
 	tcp_segment_t *nseg;
@@ -319,10 +319,10 @@
 
 /** Encode outgoing PDU */
-int tcp_pdu_encode(inet_ep2_t *epp, tcp_segment_t *seg, tcp_pdu_t **pdu)
+errno_t tcp_pdu_encode(inet_ep2_t *epp, tcp_segment_t *seg, tcp_pdu_t **pdu)
 {
 	tcp_pdu_t *npdu;
 	size_t text_size;
 	uint16_t checksum;
-	int rc;
+	errno_t rc;
 
 	npdu = tcp_pdu_new();
Index: uspace/srv/net/tcp/pdu.h
===================================================================
--- uspace/srv/net/tcp/pdu.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/pdu.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -43,6 +43,6 @@
 extern tcp_pdu_t *tcp_pdu_create(void *, size_t, void *, size_t);
 extern void tcp_pdu_delete(tcp_pdu_t *);
-extern int tcp_pdu_decode(tcp_pdu_t *, inet_ep2_t *, tcp_segment_t **);
-extern int tcp_pdu_encode(inet_ep2_t *, tcp_segment_t *, tcp_pdu_t **);
+extern errno_t tcp_pdu_decode(tcp_pdu_t *, inet_ep2_t *, tcp_segment_t **);
+extern errno_t tcp_pdu_encode(inet_ep2_t *, tcp_segment_t *, tcp_pdu_t **);
 
 #endif
Index: uspace/srv/net/tcp/rqueue.c
===================================================================
--- uspace/srv/net/tcp/rqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/rqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -105,5 +105,5 @@
 
 /** Receive queue handler fibril. */
-static int tcp_rqueue_fibril(void *arg)
+static errno_t tcp_rqueue_fibril(void *arg)
 {
 	link_t *link;
Index: uspace/srv/net/tcp/service.c
===================================================================
--- uspace/srv/net/tcp/service.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/service.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -68,5 +68,5 @@
 static void tcp_service_lst_cstate_change(tcp_conn_t *, void *, tcp_cstate_t);
 
-static int tcp_cconn_create(tcp_client_t *, tcp_conn_t *, tcp_cconn_t **);
+static errno_t tcp_cconn_create(tcp_client_t *, tcp_conn_t *, tcp_cconn_t **);
 
 /** Connection callbacks to tie us to lower layer */
@@ -132,5 +132,5 @@
 	tcp_cconn_t *cconn;
 	inet_ep2_t epp;
-	int rc;
+	errno_t rc;
 	tcp_error_t trc;
 
@@ -298,5 +298,5 @@
  * @return EOK on success or ENOMEM if out of memory
  */
-static int tcp_cconn_create(tcp_client_t *client, tcp_conn_t *conn,
+static errno_t tcp_cconn_create(tcp_client_t *client, tcp_conn_t *conn,
     tcp_cconn_t **rcconn)
 {
@@ -345,5 +345,5 @@
  * @return EOK on success or ENOMEM if out of memory
  */
-static int tcp_clistener_create(tcp_client_t *client, tcp_conn_t *conn,
+static errno_t tcp_clistener_create(tcp_client_t *client, tcp_conn_t *conn,
     tcp_clst_t **rclst)
 {
@@ -390,5 +390,5 @@
  *         is found.
  */
-static int tcp_cconn_get(tcp_client_t *client, sysarg_t id,
+static errno_t tcp_cconn_get(tcp_client_t *client, sysarg_t id,
     tcp_cconn_t **rcconn)
 {
@@ -412,5 +412,5 @@
  *         is found.
  */
-static int tcp_clistener_get(tcp_client_t *client, sysarg_t id,
+static errno_t tcp_clistener_get(tcp_client_t *client, sysarg_t id,
     tcp_clst_t **rclst)
 {
@@ -435,10 +435,10 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_create_impl(tcp_client_t *client, inet_ep2_t *epp,
+static errno_t tcp_conn_create_impl(tcp_client_t *client, inet_ep2_t *epp,
     sysarg_t *rconn_id)
 {
 	tcp_conn_t *conn;
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 	tcp_error_t trc;
 	char *slocal;
@@ -482,8 +482,8 @@
  * @return EOK on success, ENOENT if no such connection is found
  */
-static int tcp_conn_destroy_impl(tcp_client_t *client, sysarg_t conn_id)
+static errno_t tcp_conn_destroy_impl(tcp_client_t *client, sysarg_t conn_id)
 {
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 
 	rc = tcp_cconn_get(client, conn_id, &cconn);
@@ -509,5 +509,5 @@
  * @return EOK on success or an error code
 */
-static int tcp_listener_create_impl(tcp_client_t *client, inet_ep_t *ep,
+static errno_t tcp_listener_create_impl(tcp_client_t *client, inet_ep_t *ep,
     sysarg_t *rlst_id)
 {
@@ -515,5 +515,5 @@
 	tcp_clst_t *clst;
 	inet_ep2_t epp;
-	int rc;
+	errno_t rc;
 	tcp_error_t trc;
 
@@ -555,8 +555,8 @@
  * @return EOK on success, ENOENT if no such listener is found
  */
-static int tcp_listener_destroy_impl(tcp_client_t *client, sysarg_t lst_id)
+static errno_t tcp_listener_destroy_impl(tcp_client_t *client, sysarg_t lst_id)
 {
 	tcp_clst_t *clst;
-	int rc;
+	errno_t rc;
 
 	rc = tcp_clistener_get(client, lst_id, &clst);
@@ -580,8 +580,8 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_send_fin_impl(tcp_client_t *client, sysarg_t conn_id)
+static errno_t tcp_conn_send_fin_impl(tcp_client_t *client, sysarg_t conn_id)
 {
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 
 	rc = tcp_cconn_get(client, conn_id, &cconn);
@@ -605,8 +605,8 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_push_impl(tcp_client_t *client, sysarg_t conn_id)
+static errno_t tcp_conn_push_impl(tcp_client_t *client, sysarg_t conn_id)
 {
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 
 	rc = tcp_cconn_get(client, conn_id, &cconn);
@@ -630,8 +630,8 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_reset_impl(tcp_client_t *client, sysarg_t conn_id)
+static errno_t tcp_conn_reset_impl(tcp_client_t *client, sysarg_t conn_id)
 {
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 
 	rc = tcp_cconn_get(client, conn_id, &cconn);
@@ -656,9 +656,9 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_send_impl(tcp_client_t *client, sysarg_t conn_id,
+static errno_t tcp_conn_send_impl(tcp_client_t *client, sysarg_t conn_id,
     void *data, size_t size)
 {
 	tcp_cconn_t *cconn;
-	int rc;
+	errno_t rc;
 	tcp_error_t trc;
 
@@ -686,10 +686,10 @@
  * @return EOK on success or an error code
  */
-static int tcp_conn_recv_impl(tcp_client_t *client, sysarg_t conn_id,
+static errno_t tcp_conn_recv_impl(tcp_client_t *client, sysarg_t conn_id,
     void *data, size_t size, size_t *nrecv)
 {
 	tcp_cconn_t *cconn;
 	xflags_t xflags;
-	int rc;
+	errno_t rc;
 	tcp_error_t trc;
 
@@ -758,5 +758,5 @@
 	inet_ep2_t epp;
 	sysarg_t conn_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_create_srv()");
@@ -802,5 +802,5 @@
 {
 	sysarg_t conn_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_destroy_srv()");
@@ -826,5 +826,5 @@
 	inet_ep_t ep;
 	sysarg_t lst_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_listener_create_srv()");
@@ -870,5 +870,5 @@
 {
 	sysarg_t lst_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_listener_destroy_srv()");
@@ -891,5 +891,5 @@
 {
 	sysarg_t conn_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_send_fin_srv()");
@@ -912,5 +912,5 @@
 {
 	sysarg_t conn_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_push_srv()");
@@ -933,5 +933,5 @@
 {
 	sysarg_t conn_id;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_reset_srv()");
@@ -957,5 +957,5 @@
 	sysarg_t conn_id;
 	void *data;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_send_srv())");
@@ -1018,5 +1018,5 @@
 	size_t size, rsize;
 	void *data;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_srv()");
@@ -1074,5 +1074,5 @@
 	size_t size, rsize;
 	void *data;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv()");
@@ -1246,7 +1246,7 @@
  * @return EOK on success or an error code.
  */
-int tcp_service_init(void)
-{
-	int rc;
+errno_t tcp_service_init(void)
+{
+	errno_t rc;
 	service_id_t sid;
 
Index: uspace/srv/net/tcp/service.h
===================================================================
--- uspace/srv/net/tcp/service.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/service.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -36,5 +36,5 @@
 #define SERVICE_H
 
-extern int tcp_service_init(void);
+extern errno_t tcp_service_init(void);
 
 #endif
Index: uspace/srv/net/tcp/tcp.c
===================================================================
--- uspace/srv/net/tcp/tcp.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/tcp.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -55,7 +55,7 @@
 };
 
-static int tcp_init(void)
+static errno_t tcp_init(void)
 {
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_init()");
@@ -91,5 +91,5 @@
 int main(int argc, char **argv)
 {
-	int rc;
+	errno_t rc;
 
 	printf(NAME ": TCP (Transmission Control Protocol) network module\n");
Index: uspace/srv/net/tcp/test.c
===================================================================
--- uspace/srv/net/tcp/test.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -47,5 +47,5 @@
 #define RCV_BUF_SIZE 64
 
-static int test_srv(void *arg)
+static errno_t test_srv(void *arg)
 {
 	tcp_conn_t *conn;
@@ -91,5 +91,5 @@
 }
 
-static int test_cli(void *arg)
+static errno_t test_cli(void *arg)
 {
 	tcp_conn_t *conn;
Index: uspace/srv/net/tcp/test/conn.c
===================================================================
--- uspace/srv/net/tcp/test/conn.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/conn.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -46,5 +46,5 @@
 PCUT_TEST_BEFORE
 {
-	int rc;
+	errno_t rc;
 
 	/* We will be calling functions that perform logging */
@@ -89,5 +89,5 @@
 	tcp_conn_t *conn, *cfound;
 	inet_ep2_t epp;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
@@ -119,5 +119,5 @@
 	tcp_conn_t *conn;
 	inet_ep2_t epp;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
@@ -152,5 +152,5 @@
 	tcp_conn_t *cconn, *sconn;
 	inet_ep2_t cepp, sepp;
-	int rc;
+	errno_t rc;
 
 	/* Client EPP */
Index: uspace/srv/net/tcp/test/iqueue.c
===================================================================
--- uspace/srv/net/tcp/test/iqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/iqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -45,5 +45,5 @@
 	inet_ep2_t epp;
 	tcp_segment_t *rseg;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
@@ -71,5 +71,5 @@
 	void *data;
 	size_t dsize;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
@@ -117,5 +117,5 @@
 	void *data;
 	size_t dsize;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
Index: uspace/srv/net/tcp/test/pdu.c
===================================================================
--- uspace/srv/net/tcp/test/pdu.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/pdu.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -47,5 +47,5 @@
 	tcp_pdu_t *pdu;
 	inet_ep2_t epp, depp;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
@@ -78,5 +78,5 @@
 	uint8_t *data;
 	size_t i, dsize;
-	int rc;
+	errno_t rc;
 
 	inet_ep2_init(&epp);
Index: uspace/srv/net/tcp/test/rqueue.c
===================================================================
--- uspace/srv/net/tcp/test/rqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/rqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -59,5 +59,5 @@
 PCUT_TEST_BEFORE
 {
-	int rc;
+	errno_t rc;
 
 	/* We will be calling functions that perform logging */
Index: uspace/srv/net/tcp/test/tqueue.c
===================================================================
--- uspace/srv/net/tcp/test/tqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/tqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -53,5 +53,5 @@
 PCUT_TEST_BEFORE
 {
-	int rc;
+	errno_t rc;
 
 	/* We will be calling functions that perform logging */
Index: uspace/srv/net/tcp/test/ucall.c
===================================================================
--- uspace/srv/net/tcp/test/ucall.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/test/ucall.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -60,5 +60,5 @@
 PCUT_TEST_BEFORE
 {
-	int rc;
+	errno_t rc;
 
 	/* We will be calling functions that perform logging */
Index: uspace/srv/net/tcp/tqueue.c
===================================================================
--- uspace/srv/net/tcp/tqueue.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/tqueue.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -63,5 +63,5 @@
 static void tcp_tqueue_send_immed(tcp_conn_t *, tcp_segment_t *);
 
-int tcp_tqueue_init(tcp_tqueue_t *tqueue, tcp_conn_t *conn,
+errno_t tcp_tqueue_init(tcp_tqueue_t *tqueue, tcp_conn_t *conn,
     tcp_tqueue_cb_t *cb)
 {
Index: uspace/srv/net/tcp/tqueue.h
===================================================================
--- uspace/srv/net/tcp/tqueue.h	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/tqueue.h	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -40,5 +40,5 @@
 #include "tcp_type.h"
 
-extern int tcp_tqueue_init(tcp_tqueue_t *, tcp_conn_t *,
+extern errno_t tcp_tqueue_init(tcp_tqueue_t *, tcp_conn_t *,
     tcp_tqueue_cb_t *);
 extern void tcp_tqueue_clear(tcp_tqueue_t *);
Index: uspace/srv/net/tcp/ucall.c
===================================================================
--- uspace/srv/net/tcp/ucall.c	(revision cde999aca79219e8751af76502001a86d411d176)
+++ uspace/srv/net/tcp/ucall.c	(revision a53ed3a8097360ccf174e8d94fb407db919eb66a)
@@ -69,5 +69,5 @@
 {
 	tcp_conn_t *nconn;
-	int rc;
+	errno_t rc;
 
 	log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_uc_open(%p, %s, %s, %p)",