diff -ru orig/MoBlock-0.8/MoBlock.c new/MoBlock-0.8/MoBlock.c
--- orig/MoBlock-0.8/MoBlock.c	2009-09-03 13:37:35.346736734 -0500
+++ new/MoBlock-0.8/MoBlock.c	2009-09-03 13:40:24.963491807 -0500
@@ -33,6 +33,7 @@
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <linux/netfilter_ipv4.h>
+#include <linux/version.h>
 #include <signal.h>
 #include <regex.h>
 
@@ -502,7 +503,9 @@
 
 	if (nfq_unbind_pf(h, AF_INET) < 0) {
 		fprintf(logfile, "error during nfq_unbind_pf()\n");
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23)
 		exit(-1);
+#endif
 	}
 
 	if (nfq_bind_pf(h, AF_INET) < 0) {