diff --git a/src/drivers/usb/usbhub.c b/src/drivers/usb/usbhub.c
index a3e7bc00c..7095fc31b 100644
--- a/src/drivers/usb/usbhub.c
+++ b/src/drivers/usb/usbhub.c
@@ -155,6 +155,10 @@ static int hub_open ( struct usb_hub *hub ) {
 	/* Refill interrupt ring */
 	hub_refill ( hubdev );
 
+	/* Delay to allow ports to stabilise on out-of-spec hubs */
+	if ( hubdev->flags & USB_HUB_SLOW_START )
+		mdelay ( USB_HUB_SLOW_START_DELAY_MS );
+
 	return 0;
 
 	usb_endpoint_close ( &hubdev->intr );
@@ -410,6 +414,7 @@ static int hub_probe ( struct usb_function *func,
 	hubdev->usb = usb;
 	hubdev->features =
 		( enhanced ? USB_HUB_FEATURES_ENHANCED : USB_HUB_FEATURES );
+	hubdev->flags = func->id->driver_data;
 	usb_endpoint_init ( &hubdev->intr, usb, &usb_hub_intr_operations );
 	usb_refill_init ( &hubdev->intr, 0, USB_HUB_INTR_FILL );
 	process_init_stopped ( &hubdev->refill, &hub_refill_desc, NULL );
@@ -517,6 +522,12 @@ static void hub_remove ( struct usb_function *func ) {
 
 /** USB hub device IDs */
 static struct usb_device_id hub_ids[] = {
+	{
+		.name = "avocent-hub",
+		.vendor = 0x0624,
+		.product = 0x0248,
+		.driver_data = USB_HUB_SLOW_START,
+	},
 	{
 		.name = "hub",
 		.vendor = USB_ANY_ID,
diff --git a/src/drivers/usb/usbhub.h b/src/drivers/usb/usbhub.h
index d7d8f9610..a5f123acc 100644
--- a/src/drivers/usb/usbhub.h
+++ b/src/drivers/usb/usbhub.h
@@ -257,6 +257,8 @@ struct usb_hub_device {
 	struct usb_hub *hub;
 	/** Features */
 	unsigned int features;
+	/** Flags */
+	unsigned int flags;
 
 	/** Interrupt endpoint */
 	struct usb_endpoint intr;
@@ -264,6 +266,12 @@ struct usb_hub_device {
 	struct process refill;
 };
 
+/** Hub requires additional settling delay */
+#define USB_HUB_SLOW_START 0x0001
+
+/** Additional setting delay for out-of-spec hubs */
+#define USB_HUB_SLOW_START_DELAY_MS 500
+
 /** Interrupt ring fill level
  *
  * This is a policy decision.