diff --git a/lib/zclient.h b/lib/zclient.h
index aa935c1..a14f599 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -96,6 +96,7 @@
 #define ZAPI_MESSAGE_IFINDEX  0x02
 #define ZAPI_MESSAGE_DISTANCE 0x04
 #define ZAPI_MESSAGE_METRIC   0x08
+#define ZAPI_MESSAGE_MTU      0x10
 
 /* Zserv protocol message header */
 struct zserv_header
@@ -131,6 +132,8 @@
 
   u_int32_t metric;
 
+  u_int32_t mtu;
+
   vrf_id_t vrf_id;
 };
 
@@ -204,6 +207,8 @@
 
   u_int32_t metric;
 
+  u_int32_t mtu;
+
   vrf_id_t vrf_id;
 };