diff --git a/lib/zclient.h b/lib/zclient.h
index a3452eb..810c927 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -99,6 +99,7 @@
 #define ZAPI_MESSAGE_DISTANCE 0x04
 #define ZAPI_MESSAGE_METRIC   0x08
 #define ZAPI_MESSAGE_MTU      0x10
+#define ZAPI_MESSAGE_TAG      0x20
 
 /* Zserv protocol message header */
 struct zserv_header
@@ -132,6 +133,8 @@
 
   u_char distance;
 
+  u_short tag;
+
   u_int32_t metric;
 
   u_int32_t mtu;
@@ -210,6 +213,8 @@
 
   u_char distance;
 
+  u_short tag;
+
   u_int32_t metric;
 
   u_int32_t mtu;