diff --git a/src/datagram.c b/src/datagram.c
index 8b68244..afae3e7 100644
--- a/src/datagram.c
+++ b/src/datagram.c
@@ -95,7 +95,7 @@ static int osmo_dgram_tx_write(struct osmo_dgram_tx *conn)
 	LOGP(DLINP, LOGL_DEBUG, "sending data\n");
 
 	if (llist_empty(&conn->tx_queue)) {
-		conn->ofd.when &= ~OSMO_FD_WRITE;
+		osmo_fd_write_disable(&conn->ofd);
 		return 0;
 	}
 	lh = conn->tx_queue.next;
@@ -236,7 +236,7 @@ void osmo_dgram_tx_send(struct osmo_dgram_tx *conn,
 				 struct msgb *msg)
 {
 	msgb_enqueue(&conn->tx_queue, msg);
-	conn->ofd.when |= OSMO_FD_WRITE;
+	osmo_fd_write_enable(&conn->ofd);
 }
 
 /*
diff --git a/src/rs232.c b/src/rs232.c
index 865ec97..b20c111 100644
--- a/src/rs232.c
+++ b/src/rs232.c
@@ -62,7 +62,7 @@ void rs232_tx_timer_cb(void *ptr)
 	struct osmo_rs232 *r = ptr;
 
 	/* we're again ready to transmit. */
-	r->ofd.when |= OSMO_FD_WRITE;
+	osmo_fd_write_enable(&r->ofd);
 }
 
 static int handle_ser_write(struct osmo_fd *bfd)
@@ -75,7 +75,7 @@ static int handle_ser_write(struct osmo_fd *bfd)
 	LOGP(DLINP, LOGL_DEBUG, "writing data to rs232\n");
 
 	if (llist_empty(&r->tx_queue)) {
-		r->ofd.when &= ~OSMO_FD_WRITE;
+		osmo_fd_write_disable(&r->ofd);
 		return 0;
 	}
 	lh = r->tx_queue.next;
@@ -92,7 +92,7 @@ static int handle_ser_write(struct osmo_fd *bfd)
 
 	/* We've got more data to write, but we have to wait to make it. */
 	if (!llist_empty(&r->tx_queue) && r->cfg.delay_us) {
-		r->ofd.when &= ~OSMO_FD_WRITE;
+		osmo_fd_write_disable(&r->ofd);
 		osmo_timer_schedule(&r->tx_timer, 0, r->cfg.delay_us);
 	}
 	return 0;
@@ -255,7 +255,7 @@ int osmo_rs232_read(struct osmo_rs232 *r, struct msgb *msg)
 void osmo_rs232_write(struct osmo_rs232 *r, struct msgb *msg)
 {
 	msgb_enqueue(&r->tx_queue, msg);
-	r->ofd.when |= OSMO_FD_WRITE;
+	osmo_fd_write_enable(&r->ofd);
 }
 
 void osmo_rs232_close(struct osmo_rs232 *r)
diff --git a/src/stream.c b/src/stream.c
index 3376126..e4fb668 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -335,7 +335,7 @@ static int osmo_stream_cli_write(struct osmo_stream_cli *cli)
 	int ret;
 
 	if (llist_empty(&cli->tx_queue)) {
-		cli->ofd.when &= ~OSMO_FD_WRITE;
+		osmo_fd_write_disable(&cli->ofd);
 		return 0;
 	}
 	lh = cli->tx_queue.next;
@@ -391,7 +391,7 @@ static int osmo_stream_cli_fd_cb(struct osmo_fd *ofd, unsigned int what)
 		/* If messages got enqueued while 'connecting', keep WRITE flag
 		   up to dispatch them upon next main loop step */
 		if (llist_empty(&cli->tx_queue))
-			cli->ofd.when &= ~OSMO_FD_WRITE;
+			osmo_fd_write_disable(&cli->ofd);
 
 		LOGSCLI(cli, LOGL_DEBUG, "connection done.\n");
 		cli->state = STREAM_CLI_STATE_CONNECTED;
@@ -787,7 +787,7 @@ static void cli_timer_cb(void *data)
 void osmo_stream_cli_send(struct osmo_stream_cli *cli, struct msgb *msg)
 {
 	msgb_enqueue(&cli->tx_queue, msg);
-	cli->ofd.when |= OSMO_FD_WRITE;
+	osmo_fd_write_enable(&cli->ofd);
 }
 
 /*! \brief Receive data via an Osmocom stream client
@@ -1137,7 +1137,7 @@ static void osmo_stream_srv_write(struct osmo_stream_srv *conn)
 	LOGP(DLINP, LOGL_DEBUG, "sending data\n");
 
 	if (llist_empty(&conn->tx_queue)) {
-		conn->ofd.when &= ~OSMO_FD_WRITE;
+		osmo_fd_write_disable(&conn->ofd);
 		return;
 	}
 	lh = conn->tx_queue.next;
@@ -1287,7 +1287,7 @@ void osmo_stream_srv_send(struct osmo_stream_srv *conn, struct msgb *msg)
 	}
 
 	msgb_enqueue(&conn->tx_queue, msg);
-	conn->ofd.when |= OSMO_FD_WRITE;
+	osmo_fd_write_enable(&conn->ofd);
 }
 
 /*! \brief Receive data via Osmocom stream server