diff --git a/service/native/include/Common.h b/service/native/include/Common.h
index 3f28991..03f449a 100644
--- a/service/native/include/Common.h
+++ b/service/native/include/Common.h
@@ -17,9 +17,12 @@
 #pragma once
 // TODO: deduplicate with the constants in NetdConstants.h.
 #include <aidl/android/net/INetd.h>
+#include "clat_mark.h"
 
 using aidl::android::net::INetd;
 
+static_assert(INetd::CLAT_MARK == CLAT_MARK, "must be 0xDEADC1A7");
+
 enum FirewallRule { ALLOW = INetd::FIREWALL_RULE_ALLOW, DENY = INetd::FIREWALL_RULE_DENY };
 
 // ALLOWLIST means the firewall denies all by default, uids must be explicitly ALLOWed