diff --git a/src/drivers/bus/usb.c b/src/drivers/bus/usb.c
index 53501b46c..a3718d831 100644
--- a/src/drivers/bus/usb.c
+++ b/src/drivers/bus/usb.c
@@ -243,7 +243,6 @@ int usb_endpoint_described ( struct usb_endpoint *ep,
 			     struct usb_interface_descriptor *interface,
 			     unsigned int type, unsigned int index ) {
 	struct usb_device *usb = ep->usb;
-	struct usb_port *port = usb->port;
 	struct usb_endpoint_descriptor *desc;
 	struct usb_endpoint_companion_descriptor *descx;
 	unsigned int sizes;
@@ -267,7 +266,7 @@ int usb_endpoint_described ( struct usb_endpoint *ep,
 	/* Calculate interval */
 	if ( ( type & USB_ENDPOINT_ATTR_TYPE_MASK ) ==
 	     USB_ENDPOINT_ATTR_INTERRUPT ) {
-		if ( port->speed >= USB_SPEED_HIGH ) {
+		if ( usb->speed >= USB_SPEED_HIGH ) {
 			/* 2^(desc->interval-1) is a microframe count */
 			interval = ( 1 << ( desc->interval - 1 ) );
 		} else {
@@ -1492,8 +1491,9 @@ static int register_usb ( struct usb_device *usb ) {
 		       hub->name, port->address, strerror ( rc ) );
 		goto err_speed;
 	}
+	usb->speed = port->speed;
 	DBGC2 ( usb, "USB %s attached as %s-speed device\n",
-		usb->name, usb_speed_name ( port->speed ) );
+		usb->name, usb_speed_name ( usb->speed ) );
 
 	/* Open device */
 	if ( ( rc = usb->host->open ( usb ) ) != 0 ) {
@@ -1503,7 +1503,7 @@ static int register_usb ( struct usb_device *usb ) {
 	}
 
 	/* Describe control endpoint */
-	mtu = USB_EP0_DEFAULT_MTU ( port->speed );
+	mtu = USB_EP0_DEFAULT_MTU ( usb->speed );
 	usb_endpoint_describe ( &usb->control, USB_EP0_ADDRESS,
 				USB_EP0_ATTRIBUTES, mtu, USB_EP0_BURST,
 				USB_EP0_INTERVAL );
@@ -1554,7 +1554,7 @@ static int register_usb ( struct usb_device *usb ) {
 	       le16_to_cpu ( usb->device.product ), usb->device.class.class,
 	       usb->device.class.subclass, usb->device.class.protocol,
 	       usb_bcd ( le16_to_cpu ( usb->device.protocol ) ),
-	       usb_speed_name ( port->speed ), usb->control.mtu );
+	       usb_speed_name ( usb->speed ), usb->control.mtu );
 
 	/* Configure device */
 	if ( ( rc = usb_autoconfigure ( usb ) ) != 0 )
@@ -2233,12 +2233,12 @@ struct usb_port * usb_transaction_translator ( struct usb_device *usb ) {
 	struct usb_device *parent;
 
 	/* Navigate up to root hub.  If we find a low-speed or
-	 * full-speed port with a higher-speed parent device, then
-	 * that port is the transaction translator.
+	 * full-speed device with a higher-speed parent hub, then that
+	 * device's port is the transaction translator.
 	 */
 	for ( ; ( parent = usb->port->hub->usb ) ; usb = parent ) {
-		if ( ( usb->port->speed <= USB_SPEED_FULL ) &&
-		     ( parent->port->speed > USB_SPEED_FULL ) )
+		if ( ( usb->speed <= USB_SPEED_FULL ) &&
+		     ( parent->speed > USB_SPEED_FULL ) )
 			return usb->port;
 	}
 
diff --git a/src/drivers/usb/ehci.c b/src/drivers/usb/ehci.c
index f90d6a91a..617a43b03 100644
--- a/src/drivers/usb/ehci.c
+++ b/src/drivers/usb/ehci.c
@@ -970,10 +970,10 @@ static uint32_t ehci_endpoint_characteristics ( struct usb_endpoint *ep ) {
 		chr |= EHCI_CHR_TOGGLE;
 
 	/* Determine endpoint speed */
-	if ( usb->port->speed == USB_SPEED_HIGH ) {
+	if ( usb->speed == USB_SPEED_HIGH ) {
 		chr |= EHCI_CHR_EPS_HIGH;
 	} else {
-		if ( usb->port->speed == USB_SPEED_FULL ) {
+		if ( usb->speed == USB_SPEED_FULL ) {
 			chr |= EHCI_CHR_EPS_FULL;
 		} else {
 			chr |= EHCI_CHR_EPS_LOW;
diff --git a/src/drivers/usb/uhci.c b/src/drivers/usb/uhci.c
index 4220bef72..528c1be1d 100644
--- a/src/drivers/usb/uhci.c
+++ b/src/drivers/usb/uhci.c
@@ -697,7 +697,7 @@ static int uhci_endpoint_open ( struct usb_endpoint *ep ) {
 		goto err_ring_alloc;
 	endpoint->ring.mtu = ep->mtu;
 	endpoint->ring.flags = UHCI_FL_CERR_MAX;
-	if ( usb->port->speed < USB_SPEED_FULL )
+	if ( usb->speed < USB_SPEED_FULL )
 		endpoint->ring.flags |= UHCI_FL_LS;
 	endpoint->ring.control = ( UHCI_CONTROL_DEVICE ( usb->address ) |
 				   UHCI_CONTROL_ENDPOINT ( ep->address ) );
diff --git a/src/drivers/usb/xhci.c b/src/drivers/usb/xhci.c
index 110b43287..67de0a832 100644
--- a/src/drivers/usb/xhci.c
+++ b/src/drivers/usb/xhci.c
@@ -2753,7 +2753,6 @@ static void xhci_device_close ( struct usb_device *usb ) {
 static int xhci_device_address ( struct usb_device *usb ) {
 	struct xhci_slot *slot = usb_get_hostdata ( usb );
 	struct xhci_device *xhci = slot->xhci;
-	struct usb_port *port = usb->port;
 	struct usb_port *root_port;
 	int psiv;
 	int rc;
@@ -2766,7 +2765,7 @@ static int xhci_device_address ( struct usb_device *usb ) {
 	slot->port = root_port->address;
 
 	/* Calculate protocol speed ID */
-	psiv = xhci_port_psiv ( xhci, slot->port, port->speed );
+	psiv = xhci_port_psiv ( xhci, slot->port, usb->speed );
 	if ( psiv < 0 ) {
 		rc = psiv;
 		return rc;
diff --git a/src/include/ipxe/usb.h b/src/include/ipxe/usb.h
index b3ce7b741..c268988f4 100644
--- a/src/include/ipxe/usb.h
+++ b/src/include/ipxe/usb.h
@@ -698,6 +698,8 @@ struct usb_device {
 	char name[32];
 	/** USB port */
 	struct usb_port *port;
+	/** Device speed */
+	unsigned int speed;
 	/** List of devices on this bus */
 	struct list_head list;
 	/** Device address, if assigned */