diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index edcbd10..3784f33 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -66,7 +66,7 @@
 ''',
                      c_type=ret_type.c_type())
 
-    if arg_type:
+    if arg_type and arg_type.members:
         ret += mcgen('''
     QmpInputVisitor *qiv = qmp_input_visitor_new_strict(QOBJECT(args));
     QapiDeallocVisitor *qdv;
@@ -98,7 +98,7 @@
 def gen_marshal_input_visit(arg_type, dealloc=False):
     ret = ''
 
-    if not arg_type:
+    if not arg_type or not arg_type.members:
         return ret
 
     if dealloc:
diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index 728659e..e722748 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -18,6 +18,8 @@
 { 'struct': 'Empty1', 'data': { } }
 { 'struct': 'Empty2', 'base': 'Empty1', 'data': { } }
 
+{ 'command': 'user_def_cmd0', 'data': 'Empty2', 'returns': 'Empty2' }
+
 # for testing override of default naming heuristic
 { 'enum': 'QEnumTwo',
   'prefix': 'QENUM_TWO',
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index f5e2a73..f531961 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -203,6 +203,8 @@
    gen=True success_response=True
 command user_def_cmd None -> None
    gen=True success_response=True
+command user_def_cmd0 Empty2 -> Empty2
+   gen=True success_response=True
 command user_def_cmd1 :obj-user_def_cmd1-arg -> None
    gen=True success_response=True
 command user_def_cmd2 :obj-user_def_cmd2-arg -> UserDefTwo
diff --git a/tests/test-qmp-commands.c b/tests/test-qmp-commands.c
index d6171f2..650ba46 100644
--- a/tests/test-qmp-commands.c
+++ b/tests/test-qmp-commands.c
@@ -13,6 +13,11 @@
 {
 }
 
+Empty2 *qmp_user_def_cmd0(Error **errp)
+{
+    return g_new0(Empty2, 1);
+}
+
 void qmp_user_def_cmd1(UserDefOne * ud1, Error **errp)
 {
 }