--- cowloop-3.0/src/cowloop.c.orig	2006-12-22 18:31:13.000000000 +1100
+++ cowloop-3.0/src/cowloop.c	2008-01-30 00:03:55.000000000 +0200
@@ -2816,9 +2816,13 @@
 	for (minor=0; minor < maxcows;  minor++)
 		(void) cowlo_closepair(cowdevall[minor]);
 
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23))
 	if (unregister_blkdev(COWMAJOR, DEVICE_NAME) != 0)
 		printk(KERN_WARNING "cowloop - cannot unregister blkdev\n");
+#else
+	unregister_blkdev(COWMAJOR, DEVICE_NAME);
+#endif
 
 	/*
 	** get rid of /proc/cow and unregister the driver
 	*/