diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c
index 0164984ec647463402279d4b91a8df4927019ff2..0d0c85989a3db88ade2da5661ee71630b4ca63d7 100644
--- a/tests/test-qmp-output-visitor.c
+++ b/tests/test-qmp-output-visitor.c
@@ -425,8 +425,9 @@ static void test_visitor_out_alternate(TestOutputVisitorData *data,
                                        const void *unused)
 {
     QObject *arg;
+    UserDefAlternate *tmp;
 
-    UserDefAlternate *tmp = g_malloc0(sizeof(UserDefAlternate));
+    tmp = g_new0(UserDefAlternate, 1);
     tmp->type = USER_DEF_ALTERNATE_KIND_I;
     tmp->u.i = 42;
 
@@ -438,6 +439,19 @@ static void test_visitor_out_alternate(TestOutputVisitorData *data,
 
     qapi_free_UserDefAlternate(tmp);
     qobject_decref(arg);
+
+    tmp = g_new0(UserDefAlternate, 1);
+    tmp->type = USER_DEF_ALTERNATE_KIND_S;
+    tmp->u.s = g_strdup("hello");
+
+    visit_type_UserDefAlternate(data->ov, &tmp, NULL, &error_abort);
+    arg = qmp_output_get_qobject(data->qov);
+
+    g_assert(qobject_type(arg) == QTYPE_QSTRING);
+    g_assert_cmpstr(qstring_get_str(qobject_to_qstring(arg)), ==, "hello");
+
+    qapi_free_UserDefAlternate(tmp);
+    qobject_decref(arg);
 }
 
 static void test_visitor_out_empty(TestOutputVisitorData *data,