diff --git a/extensions/libxt_MARK.t b/extensions/libxt_MARK.t
new file mode 100644
index 0000000..9d1aa7d
--- /dev/null
+++ b/extensions/libxt_MARK.t
@@ -0,0 +1,7 @@
+:INPUT,FORWARD,OUTPUT
+-j MARK --set-xmark 0xfeedcafe/0xfeedcafe;=;OK
+-j MARK --set-xmark 0;=;OK
+-j MARK --set-xmark 4294967295;-j MARK --set-xmark 0xffffffff;OK
+-j MARK --set-xmark 4294967296;;FAIL
+-j MARK --set-xmark -1;;FAIL
+-j MARK;;FAIL