Use nf_conntrack headers instead of ip_conntrack ones and add sanitized versions.
diff --git a/extensions/libipt_state.c b/extensions/libipt_state.c
index acafe9a..6a784ff 100644
--- a/extensions/libipt_state.c
+++ b/extensions/libipt_state.c
@@ -5,7 +5,7 @@
 #include <stdlib.h>
 #include <getopt.h>
 #include <iptables.h>
-#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter/nf_conntrack_common.h>
 #include <linux/netfilter_ipv4/ipt_state.h>
 
 #ifndef IPT_STATE_UNTRACKED