diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c
index b66ef68..49140f8 100644
--- a/hw/s390-virtio-bus.c
+++ b/hw/s390-virtio-bus.c
@@ -429,6 +429,7 @@
     .parent = TYPE_DEVICE,
     .instance_size = sizeof(VirtIOS390Device),
     .class_init = virtio_s390_device_class_init,
+    .class_size = sizeof(VirtIOS390DeviceClass),
     .abstract = true,
 };
 
diff --git a/vl.c b/vl.c
index 2d464cf..63dd725 100644
--- a/vl.c
+++ b/vl.c
@@ -1947,7 +1947,11 @@
     }
 
     bus_opts = qemu_opts_create(device, NULL, 0);
-    qemu_opt_set(bus_opts, "driver", "virtio-serial");
+    if (arch_type == QEMU_ARCH_S390X) {
+        qemu_opt_set(bus_opts, "driver", "virtio-serial-s390");
+    } else {
+        qemu_opt_set(bus_opts, "driver", "virtio-serial-pci");
+    } 
 
     dev_opts = qemu_opts_create(device, NULL, 0);
     qemu_opt_set(dev_opts, "driver", "virtconsole");