diff --git a/docs/pci_expander_bridge.txt b/docs/pci_expander_bridge.txt
index 3675027..7aad3d2 100644
--- a/docs/pci_expander_bridge.txt
+++ b/docs/pci_expander_bridge.txt
@@ -23,9 +23,9 @@ A detailed command line would be:
 -m 2G
 -object memory-backend-ram,size=1024M,policy=bind,host-nodes=0,id=ram-node0 -numa node,nodeid=0,cpus=0,memdev=ram-node0
 -object memory-backend-ram,size=1024M,policy=bind,host-nodes=1,id=ram-node1 -numa node,nodeid=1,cpus=1,memdev=ram-node1
--device pxb,id=bridge1,bus=pci.0,numa_node=1,bus_nr=4 -netdev user,id=nd -device e1000,bus=bridge1,addr=0x4,netdev=nd
--device pxb,id=bridge2,bus=pci.0,numa_node=0,bus_nr=8 -device e1000,bus=bridge2,addr=0x3
--device pxb,id=bridge3,bus=pci.0,bus_nr=40 -drive if=none,id=drive0,file=[img] -device virtio-blk-pci,drive=drive0,scsi=off,bus=bridge3,addr=1
+-device pxb,id=bridge1,bus=pci.0,numa_node=1,bus_nr=4,chassis_nr=1 -netdev user,id=nd -device e1000,bus=bridge1,addr=0x4,netdev=nd
+-device pxb,id=bridge2,bus=pci.0,numa_node=0,bus_nr=8,chassis_nr=2 -device e1000,bus=bridge2,addr=0x3
+-device pxb,id=bridge3,bus=pci.0,bus_nr=40,chassis_nr=3 -drive if=none,id=drive0,file=[img] -device virtio-blk-pci,drive=drive0,scsi=off,bus=bridge3,addr=1
 
 Here you have:
  - 2 NUMA nodes for the guest, 0 and 1. (both mapped to the same NUMA node in host, but you can and should put it in different host NUMA nodes)
@@ -55,4 +55,3 @@ The PXB is composed by:
   - Using the bridge will enable hotplug support
   - All the devices behind the bridge will use bridge's IO/MEM windows compacting
     the PCI address space.
-
diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index 5e7e546..124261f 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -46,6 +46,7 @@ typedef struct PXBDev {
     PCIDevice parent_obj;
     /*< public >*/
 
+    uint8_t chassis_nr;
     uint8_t bus_nr;
     uint16_t numa_node;
 } PXBDev;
@@ -237,7 +238,8 @@ static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
         bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
         bds = qdev_create(BUS(bus), "pci-bridge");
         bds->id = dev_name;
-        qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
+        qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR,
+                            pxb->chassis_nr);
         qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
     }
 
@@ -267,11 +269,17 @@ static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
 
 static int pxb_dev_initfn(PCIDevice *dev)
 {
+    PXBDev *pxb = convert_to_pxb(dev);
+
     if (pci_bus_is_express(dev->bus)) {
         error_report("pxb devices cannot reside on a PCIe bus!");
         return -EINVAL;
     }
 
+    if (!pxb->chassis_nr) {
+        pxb->chassis_nr = pxb->bus_nr;
+    }
+
     return pxb_dev_init_common(dev, false);
 }
 
@@ -286,6 +294,8 @@ static Property pxb_dev_properties[] = {
     /* Note: 0 is not a legal PXB bus number. */
     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
+    /* Note: 0 is not a legal chassis number. */
+    DEFINE_PROP_UINT8("chassis_nr", PXBDev, chassis_nr, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -322,6 +332,13 @@ static int pxb_pcie_dev_initfn(PCIDevice *dev)
     return pxb_dev_init_common(dev, true);
 }
 
+static Property pxb_pcie_dev_properties[] = {
+    /* Note: 0 is not a legal PXB bus number. */
+    DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
+    DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -334,7 +351,7 @@ static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
     k->class_id = PCI_CLASS_BRIDGE_HOST;
 
     dc->desc = "PCI Express Expander Bridge";
-    dc->props = pxb_dev_properties;
+    dc->props = pxb_pcie_dev_properties;
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
 }
 
