diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 6d4f64e..8dca87c 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -38,6 +38,8 @@
 
 #define VIRTIO_PCI_REGION_SIZE(dev)     VIRTIO_PCI_CONFIG_OFF(msix_present(dev))
 
+#undef VIRTIO_PCI_CONFIG
+
 /* The remaining space is defined by each driver as the per-driver
  * configuration space */
 #define VIRTIO_PCI_CONFIG_SIZE(dev)     VIRTIO_PCI_CONFIG_OFF(msix_enabled(dev))