--- libtopfield/usb_io.h.orig	2008-12-26 23:11:08.000000000 -0600
+++ libtopfield/usb_io.h	2008-12-26 23:24:02.000000000 -0600
@@ -36,7 +36,12 @@
 
 /* linux/usb_ch9.h wasn't separated out until 2.4.23 */
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,23)
+/* and then moved to linux/usb/ch9.h at 2.6.23. */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
+#include <linux/usb/ch9.h>
+#else
 #include <linux/usb_ch9.h>
+#endif
 #else
 #include <linux/usb.h>
 #endif