diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 64dd392..22b132b 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -169,7 +169,11 @@ static void qmp_input_start_struct(Visitor *v, const char *name, void **obj,
     if (obj) {
         *obj = NULL;
     }
-    if (!qobj || qobject_type(qobj) != QTYPE_QDICT) {
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
+    if (qobject_type(qobj) != QTYPE_QDICT) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "QDict");
         return;
@@ -194,7 +198,11 @@ static void qmp_input_start_list(Visitor *v, const char *name,
     QObject *qobj = qmp_input_get_object(qiv, name, true);
     const QListEntry *entry;
 
-    if (!qobj || qobject_type(qobj) != QTYPE_QLIST) {
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
+    if (qobject_type(qobj) != QTYPE_QLIST) {
         if (list) {
             *list = NULL;
         }
@@ -234,8 +242,10 @@ static void qmp_input_start_alternate(Visitor *v, const char *name,
     QmpInputVisitor *qiv = to_qiv(v);
     QObject *qobj = qmp_input_get_object(qiv, name, false);
 
-    if (!qobj) {
+    if (obj) {
         *obj = NULL;
+    }
+    if (!qobj) {
         error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
         return;
     }
@@ -250,8 +260,13 @@ static void qmp_input_type_int64(Visitor *v, const char *name, int64_t *obj,
                                  Error **errp)
 {
     QmpInputVisitor *qiv = to_qiv(v);
-    QInt *qint = qobject_to_qint(qmp_input_get_object(qiv, name, true));
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+    QInt *qint = qobject_to_qint(qobj);
 
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     if (!qint) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "integer");
@@ -266,8 +281,13 @@ static void qmp_input_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 {
     /* FIXME: qobject_to_qint mishandles values over INT64_MAX */
     QmpInputVisitor *qiv = to_qiv(v);
-    QInt *qint = qobject_to_qint(qmp_input_get_object(qiv, name, true));
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+    QInt *qint = qobject_to_qint(qobj);
 
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     if (!qint) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "integer");
@@ -281,8 +301,13 @@ static void qmp_input_type_bool(Visitor *v, const char *name, bool *obj,
                                 Error **errp)
 {
     QmpInputVisitor *qiv = to_qiv(v);
-    QBool *qbool = qobject_to_qbool(qmp_input_get_object(qiv, name, true));
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+    QBool *qbool = qobject_to_qbool(qobj);
 
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     if (!qbool) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "boolean");
@@ -296,8 +321,16 @@ static void qmp_input_type_str(Visitor *v, const char *name, char **obj,
                                Error **errp)
 {
     QmpInputVisitor *qiv = to_qiv(v);
-    QString *qstr = qobject_to_qstring(qmp_input_get_object(qiv, name, true));
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+    QString *qstr = qobject_to_qstring(qobj);
 
+    if (obj) {
+        *obj = NULL;
+    }
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     if (!qstr) {
         *obj = NULL;
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
@@ -316,6 +349,10 @@ static void qmp_input_type_number(Visitor *v, const char *name, double *obj,
     QInt *qint;
     QFloat *qfloat;
 
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     qint = qobject_to_qint(qobj);
     if (qint) {
         *obj = qint_get_int(qobject_to_qint(qobj));
@@ -338,6 +375,14 @@ static void qmp_input_type_any(Visitor *v, const char *name, QObject **obj,
     QmpInputVisitor *qiv = to_qiv(v);
     QObject *qobj = qmp_input_get_object(qiv, name, true);
 
+    if (obj) {
+        *obj = NULL;
+    }
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
+
     qobject_incref(qobj);
     *obj = qobj;
 }
@@ -347,6 +392,10 @@ static void qmp_input_type_null(Visitor *v, const char *name, Error **errp)
     QmpInputVisitor *qiv = to_qiv(v);
     QObject *qobj = qmp_input_get_object(qiv, name, true);
 
+    if (!qobj) {
+        error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
     if (qobject_type(qobj) != QTYPE_QNULL) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "null");