Index: uspace/srv/hid/output/ctl/serial.c
===================================================================
--- uspace/srv/hid/output/ctl/serial.c	(revision bbc6277ad36dbd4db13407f458067acf6bb14623)
+++ uspace/srv/hid/output/ctl/serial.c	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -60,5 +60,5 @@
 }
 
-static int serial_yield(outdev_t *dev)
+static errno_t serial_yield(outdev_t *dev)
 {
 	vt100_state_t *state = (vt100_state_t *) dev->data;
@@ -67,5 +67,5 @@
 }
 
-static int serial_claim(outdev_t *dev)
+static errno_t serial_claim(outdev_t *dev)
 {
 	vt100_state_t *state = (vt100_state_t *) dev->data;
@@ -122,5 +122,5 @@
 };
 
-int serial_init(vt100_putchar_t putchar_fn,
+errno_t serial_init(vt100_putchar_t putchar_fn,
     vt100_control_puts_t control_puts_fn, vt100_flush_t flush_fn)
 {