Index: uspace/drv/bus/usb/usbmid/main.c
===================================================================
--- uspace/drv/bus/usb/usbmid/main.c	(revision 860bf9432c5cbca35c113c05de071907f7c924d6)
+++ uspace/drv/bus/usb/usbmid/main.c	(revision a821f057270c2924477d104a1e97d85f64d5be69)
@@ -56,7 +56,7 @@
 }
 
-static int destroy_interfaces(usb_mid_t *usb_mid)
+static errno_t destroy_interfaces(usb_mid_t *usb_mid)
 {
-	int ret = EOK;
+	errno_t ret = EOK;
 
 	while (!list_empty(&usb_mid->interface_list)) {
@@ -66,5 +66,5 @@
 		usbmid_interface_t *iface = usbmid_interface_from_link(item);
 
-		const int pret = usbmid_interface_destroy(iface);
+		const errno_t pret = usbmid_interface_destroy(iface);
 		if (pret != EOK) {
 			usb_log_error("Failed to remove child `%s': %s",
@@ -139,5 +139,5 @@
 }
 
-static int usbmid_function_online(ddf_fun_t *fun)
+static errno_t usbmid_function_online(ddf_fun_t *fun)
 {
 	usb_device_t *usb_dev = ddf_dev_data_get(ddf_fun_get_dev(fun));
Index: uspace/drv/bus/usb/usbmid/usbmid.c
===================================================================
--- uspace/drv/bus/usb/usbmid/usbmid.c	(revision 860bf9432c5cbca35c113c05de071907f7c924d6)
+++ uspace/drv/bus/usb/usbmid/usbmid.c	(revision a821f057270c2924477d104a1e97d85f64d5be69)
@@ -120,5 +120,5 @@
 	 * class name something humanly understandable.
 	 */
-	int ret = asprintf(&child_name, "%s%hhu",
+	errno_t ret = asprintf(&child_name, "%s%hhu",
 	    usb_str_class(interface_descriptor->interface_class),
 	    interface_descriptor->interface_number);