Index: uspace/lib/usb/include/usb/debug.h
===================================================================
--- uspace/lib/usb/include/usb/debug.h	(revision 5ab4a48d32c23df2eb23375a41e3ba2eec2706e0)
+++ uspace/lib/usb/include/usb/debug.h	(revision 77d10f0e0c104e3c5426b9f3cf9c196940af3cb1)
@@ -36,4 +36,5 @@
 #define LIBUSB_DEBUG_H_
 #include <stdio.h>
+#include <inttypes.h>
 #include <usb/usb.h>
 #include <assert.h>
@@ -85,5 +86,6 @@
 void usb_log_enable(usb_log_level_t, const char *);
 
-void usb_log_printf(usb_log_level_t, const char *, ...);
+void usb_log_printf(usb_log_level_t, const char *, ...)
+	PRINTF_ATTRIBUTE(2, 3);
 
 /** Log fatal error. */