diff --git a/lib/zclient.c b/lib/zclient.c
index 097314a..a1de831 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -530,6 +530,8 @@
   * If ZAPI_MESSAGE_METRIC is set, the metric value is written as an 8
   * byte value.
   *
+  * If ZAPI_MESSAGE_TAG is set, the tag value is written as a 2 byte value
+  *
   * XXX: No attention paid to alignment.
   */ 
 int
@@ -588,6 +590,8 @@
     stream_putl (s, api->metric);
   if (CHECK_FLAG (api->message, ZAPI_MESSAGE_MTU))
     stream_putl (s, api->mtu);
+  if (CHECK_FLAG (api->message, ZAPI_MESSAGE_TAG))
+    stream_putw (s, api->tag);
 
   /* Put length at the first point of the stream. */
   stream_putw_at (s, 0, stream_get_endp (s));
@@ -644,6 +648,8 @@
     stream_putl (s, api->metric);
   if (CHECK_FLAG (api->message, ZAPI_MESSAGE_MTU))
     stream_putl (s, api->mtu);
+  if (CHECK_FLAG (api->message, ZAPI_MESSAGE_TAG))
+    stream_putw (s, api->tag);
 
   /* Put length at the first point of the stream. */
   stream_putw_at (s, 0, stream_get_endp (s));