diff --git a/libc/kernel/uapi/linux/usb/ch11.h b/libc/kernel/uapi/linux/usb/ch11.h
index 41fc972..e31c37b 100644
--- a/libc/kernel/uapi/linux/usb/ch11.h
+++ b/libc/kernel/uapi/linux/usb/ch11.h
@@ -20,6 +20,7 @@
 #define __LINUX_CH11_H
 #include <linux/types.h>
 #define USB_MAXCHILDREN 31
+#define USB_SS_MAXPORTS 15
 #define USB_RT_HUB (USB_TYPE_CLASS | USB_RECIP_DEVICE)
 #define USB_RT_PORT (USB_TYPE_CLASS | USB_RECIP_OTHER)
 #define HUB_PORT_STATUS 0