diff --git a/bus/usb/usb.c b/bus/usb/usb.c
index a961e0b48..b3eaeba0e 100644
--- a/bus/usb/usb.c
+++ b/bus/usb/usb.c
@@ -209,14 +209,23 @@ grub_usb_device_initialize (grub_usb_device_t dev)
 	goto fail;
 
       /* Skip the configuration descriptor.  */
-      pos = sizeof (struct grub_usb_desc_config);
+      pos = dev->config[i].descconf->length;
 
       /* Read all interfaces.  */
       for (currif = 0; currif < dev->config[i].descconf->numif; currif++)
 	{
+	  while (pos < config.totallen
+		 && ((struct grub_usb_desc *)&data[pos])->type
+		 != GRUB_USB_DESCRIPTOR_INTERFACE)
+	    pos += ((struct grub_usb_desc *)&data[pos])->length;
 	  dev->config[i].interf[currif].descif
 	    = (struct grub_usb_desc_if *) &data[pos];
-	  pos += sizeof (struct grub_usb_desc_if);
+	  pos += dev->config[i].interf[currif].descif->length;
+
+	  while (pos < config.totallen
+		 && ((struct grub_usb_desc *)&data[pos])->type
+		 != GRUB_USB_DESCRIPTOR_ENDPOINT)
+	    pos += ((struct grub_usb_desc *)&data[pos])->length;
 
 	  /* Point to the first endpoint.  */
 	  dev->config[i].interf[currif].descendp
diff --git a/include/grub/usbdesc.h b/include/grub/usbdesc.h
index 2f711d755..84b723a62 100644
--- a/include/grub/usbdesc.h
+++ b/include/grub/usbdesc.h
@@ -31,6 +31,12 @@ typedef enum {
   GRUB_USB_DESCRIPTOR_HUB = 0x29
 } grub_usb_descriptor_t;
 
+struct grub_usb_desc
+{
+  grub_uint8_t length;
+  grub_uint8_t type;
+} __attribute__ ((packed));
+
 struct grub_usb_desc_device
 {
   grub_uint8_t length;