diff --git a/netflow/iptables.sh b/netflow/iptables.sh
index 322770a..093861b 100644
--- a/netflow/iptables.sh
+++ b/netflow/iptables.sh
@@ -20,7 +20,7 @@ __get_mount_paths_cgroup_id() {
 # __get_mount_paths_cgroup_id
 
 __get_in_cgroup_ids() {
-	awk '$0 != 1' /sys/fs/cgroup/net_cls,net_prio/*/net_cls.classid
+	awk '$0 != 0 && $0 != 1' /sys/fs/cgroup/net_cls,net_prio/*/net_cls.classid
 }
 
 __main() {