diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index 31f5286e3c..422402e564 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -227,6 +227,7 @@ static void s390_virtio_serial_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static int s390_virtio_scsi_init(VirtIOS390Device *s390_dev)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 271104d049..5d7f3a6af7 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -853,6 +853,7 @@ static void virtio_ccw_serial_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static int virtio_ccw_balloon_init(VirtioCcwDevice *ccw_dev)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 3c1f37bfe4..4446d79269 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1410,6 +1410,7 @@ static void virtio_serial_pci_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static const TypeInfo virtio_serial_pci_info = {