diff --git a/sys/dev/usb/controller/xhci.h b/sys/dev/usb/controller/xhci.h
index c0427e0cf11f..e8841a05b134 100644
--- a/sys/dev/usb/controller/xhci.h
+++ b/sys/dev/usb/controller/xhci.h
@@ -33,7 +33,7 @@
 #define	XHCI_MAX_DEVICES	MIN(USB_MAX_DEVICES, 128)
 #define	XHCI_MAX_ENDPOINTS	32	/* hardcoded - do not change */
 #define	XHCI_MAX_SCRATCHPADS	256	/* theoretical max is 1023 */
-#define	XHCI_MAX_EVENTS		(16 * 13)
+#define	XHCI_MAX_EVENTS		232
 #define	XHCI_MAX_COMMANDS	(16 * 1)
 #define	XHCI_MAX_RSEG		1
 #define	XHCI_MAX_TRANSFERS	4
@@ -383,6 +383,8 @@ struct xhci_hw_root {
 	struct xhci_trb			hwr_commands[XHCI_MAX_COMMANDS];
 };
 
+CTASSERT(sizeof(struct xhci_hw_root) == XHCI_PAGE_SIZE);
+
 struct xhci_endpoint_ext {
 	struct xhci_trb		*trb;
 	struct usb_xfer		*xfer[XHCI_MAX_TRANSFERS * XHCI_MAX_STREAMS];