diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index e5b7c9a42b..0131d9d02c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1148,11 +1148,17 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
     uint32_t addr; /* offset in pci config space */
     uint64_t wmask;
     pcibus_t size = memory_region_size(memory);
+    uint8_t hdr_type;
 
     assert(region_num >= 0);
     assert(region_num < PCI_NUM_REGIONS);
     assert(is_power_of_2(size));
 
+    /* A PCI bridge device (with Type 1 header) may only have at most 2 BARs */
+    hdr_type =
+        pci_dev->config[PCI_HEADER_TYPE] & ~PCI_HEADER_TYPE_MULTI_FUNCTION;
+    assert(hdr_type != PCI_HEADER_TYPE_BRIDGE || region_num < 2);
+
     r = &pci_dev->io_regions[region_num];
     r->addr = PCI_BAR_UNMAPPED;
     r->size = size;