Index: uspace/lib/usb/src/usb.c
===================================================================
--- uspace/lib/usb/src/usb.c	(revision 582a0b84b0a73672531e7b404a89997af41ba0b9)
+++ uspace/lib/usb/src/usb.c	(revision f4665bdceacaf4ffbcf2ed2610a92456199e2352)
@@ -73,5 +73,5 @@
 const char *usb_str_transfer_type(usb_transfer_type_t t)
 {
-	if (t >= ARRAY_SIZE(str_transfer_type)) {
+	if ((size_t)t >= ARRAY_SIZE(str_transfer_type)) {
 		return "invalid";
 	}
@@ -86,5 +86,5 @@
 const char *usb_str_transfer_type_short(usb_transfer_type_t t)
 {
-	if (t >= ARRAY_SIZE(str_transfer_type_short)) {
+	if ((size_t)t >= ARRAY_SIZE(str_transfer_type_short)) {
 		return "invl";
 	}