diff --git a/include/libvirt/virterror.h b/include/libvirt/virterror.h
index d2b5f1fd4ea73b197983af02cc7abc1554e0b6a6..91ba2978433198aed3b755ccb2700a7d3b86a9e5 100644
--- a/include/libvirt/virterror.h
+++ b/include/libvirt/virterror.h
@@ -318,7 +318,7 @@ typedef enum {
     VIR_ERR_NO_SERVER = 95,             /* Server was not found */
     VIR_ERR_NO_CLIENT = 96,             /* Client was not found */
     VIR_ERR_AGENT_UNSYNCED = 97,        /* guest agent replies with wrong id
-                                           to guest-sync command */
+                                           to guest-sync command (DEPRECATED)*/
     VIR_ERR_LIBSSH = 98,                /* error in libssh transport driver */
 } virErrorNumber;
 
diff --git a/src/util/virerror.c b/src/util/virerror.c
index 91022c3b6352b5431bc9f437114b8fc10b85f6de..562c3bc61d94acad42e480fdc47e63d6f3e462be 100644
--- a/src/util/virerror.c
+++ b/src/util/virerror.c
@@ -1441,7 +1441,7 @@ virErrorMsg(virErrorNumber error, const char *info)
             else
                 errmsg = _("Client not found: %s");
             break;
-        case VIR_ERR_AGENT_UNSYNCED:
+        case VIR_ERR_AGENT_UNSYNCED: /* DEPRECATED */
             if (info == NULL)
                 errmsg = _("guest agent replied with wrong id to guest-sync command");
             else