diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index efbaa99117..31014e8769 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -404,8 +404,7 @@ void qdev_init_gpio_out_named(DeviceState *dev, qemu_irq *pins,
     char *propname = g_strdup_printf("%s[*]", name ? name : "unnamed-gpio-out");
 
     assert(gpio_list->num_in == 0 || !name);
-    assert(gpio_list->num_out == 0);
-    gpio_list->num_out = n;
+    gpio_list->num_out += n;
 
     for (i = 0; i < n; ++i) {
         memset(&pins[i], 0, sizeof(*pins));