diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 38ffa7bcee..135695c551 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -16,7 +16,7 @@ extern bool pci_available;
 #define PCI_BUS_NUM(x)          (((x) >> 8) & 0xff)
 #define PCI_SLOT(devfn)         (((devfn) >> 3) & 0x1f)
 #define PCI_FUNC(devfn)         ((devfn) & 0x07)
-#define PCI_BUILD_BDF(bus, devfn)     ((bus << 8) | (devfn))
+#define PCI_BUILD_BDF(bus, devfn)     (((bus) << 8) | (devfn))
 #define PCI_BDF_TO_DEVFN(x)     ((x) & 0xff)
 #define PCI_BUS_MAX             256
 #define PCI_DEVFN_MAX           256