diff --git a/hw/pci-host/grackle.c b/hw/pci-host/grackle.c
index 4991ec44b0..75b60d36ac 100644
--- a/hw/pci-host/grackle.c
+++ b/hw/pci-host/grackle.c
@@ -82,7 +82,7 @@ PCIBus *pci_grackle_init(uint32_t base, qemu_irq *pic,
     memory_region_add_subregion(address_space_mem, 0x80000000ULL,
                                 &d->pci_hole);
 
-    phb->bus = pci_register_bus(dev, "pci",
+    phb->bus = pci_register_bus(dev, NULL,
                                 pci_grackle_set_irq,
                                 pci_grackle_map_irq,
                                 pic,
diff --git a/hw/pci-host/uninorth.c b/hw/pci-host/uninorth.c
index 91530cdd04..adc1d89010 100644
--- a/hw/pci-host/uninorth.c
+++ b/hw/pci-host/uninorth.c
@@ -234,7 +234,7 @@ PCIBus *pci_pmac_init(qemu_irq *pic,
     memory_region_add_subregion(address_space_mem, 0x80000000ULL,
                                 &d->pci_hole);
 
-    h->bus = pci_register_bus(dev, "pci",
+    h->bus = pci_register_bus(dev, NULL,
                               pci_unin_set_irq, pci_unin_map_irq,
                               pic,
                               &d->pci_mmio,
@@ -300,7 +300,7 @@ PCIBus *pci_pmac_u3_init(qemu_irq *pic,
     memory_region_add_subregion(address_space_mem, 0x80000000ULL,
                                 &d->pci_hole);
 
-    h->bus = pci_register_bus(dev, "pci",
+    h->bus = pci_register_bus(dev, NULL,
                               pci_unin_set_irq, pci_unin_map_irq,
                               pic,
                               &d->pci_mmio,