diff --git a/include/usb.h b/include/usb.h
index 22f6088fe6..fa9e09607e 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -103,7 +103,7 @@ enum {
  */
 struct usb_device {
 	int	devnum;			/* Device number on USB bus */
-	int	speed;			/* full/low/high */
+	enum usb_device_speed speed;	/* full/low/high */
 	char	mf[32];			/* manufacturer */
 	char	prod[32];		/* product */
 	char	serial[32];		/* serial number */