diff --git a/QMP/qmp-spec.txt b/QMP/qmp-spec.txt
index 1ba916c..a277896 100644
--- a/QMP/qmp-spec.txt
+++ b/QMP/qmp-spec.txt
@@ -106,14 +106,11 @@ completed because of an error condition.
 
 The format is:
 
-{ "error": { "class": json-string, "data": json-object, "desc": json-string },
-  "id": json-value }
+{ "error": { "class": json-string, "desc": json-string }, "id": json-value }
 
  Where,
 
-- The "class" member contains the error class name (eg. "ServiceUnavailable")
-- The "data" member contains specific error data and is defined in a
-  per-command basis, it will be an empty json-object if the error has no data
+- The "class" member contains the error class name (eg. "GenericError")
 - The "desc" member is a human-readable error message. Clients should
   not attempt to parse this message.
 - The "id" member contains the transaction identification associated with
@@ -173,8 +170,7 @@ S: {"return": {"enabled": true, "present": true}, "id": "example"}
 ------------------
 
 C: { "execute": }
-S: {"error": {"class": "JSONParsing", "desc": "Invalid JSON syntax", "data":
-{}}}
+S: {"error": {"class": "GenericError", "desc": "Invalid JSON syntax" } }
 
 3.5 Powerdown event
 -------------------
diff --git a/monitor.c b/monitor.c
index 4eeb0c5..8b00b3b 100644
--- a/monitor.c
+++ b/monitor.c
@@ -356,16 +356,26 @@ static void monitor_json_emitter(Monitor *mon, const QObject *data)
     QDECREF(json);
 }
 
+static QDict *build_qmp_error_dict(const QError *err)
+{
+    QObject *obj;
+
+    obj = qobject_from_jsonf("{ 'error': { 'class': %s, 'desc': %p } }",
+                             ErrorClass_lookup[err->err_class],
+                             qerror_human(err));
+
+    return qobject_to_qdict(obj);
+}
+
 static void monitor_protocol_emitter(Monitor *mon, QObject *data)
 {
     QDict *qmp;
 
     trace_monitor_protocol_emitter(mon);
 
-    qmp = qdict_new();
-
     if (!monitor_has_error(mon)) {
         /* success response */
+        qmp = qdict_new();
         if (data) {
             qobject_incref(data);
             qdict_put_obj(qmp, "return", data);
@@ -375,9 +385,7 @@ static void monitor_protocol_emitter(Monitor *mon, QObject *data)
         }
     } else {
         /* error response */
-        qdict_put(mon->error->error, "desc", qerror_human(mon->error));
-        qdict_put(qmp, "error", mon->error->error);
-        QINCREF(mon->error->error);
+        qmp = build_qmp_error_dict(mon->error);
         QDECREF(mon->error);
         mon->error = NULL;
     }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e3cf3c5..e520b51 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -435,8 +435,7 @@ Example:
 -> { "execute": "inject-nmi" }
 <- { "return": {} }
 
-Note: inject-nmi is only supported for x86 guest currently, it will
-      returns "Unsupported" error for non-x86 guest.
+Note: inject-nmi is only supported for x86 guests.
 
 EQMP