diff --git a/src/soc/amd/stoneyridge/northbridge.c b/src/soc/amd/stoneyridge/northbridge.c
index 75fdfa4..452a7bb 100644
--- a/src/soc/amd/stoneyridge/northbridge.c
+++ b/src/soc/amd/stoneyridge/northbridge.c
@@ -334,6 +334,8 @@
 
 	pci_domain_read_resources(dev);
 
+	fixed_io_range_reserved(dev, idx++, PCI_IO_CONFIG_INDEX, PCI_IO_CONFIG_PORT_COUNT);
+
 	/* 0x0 -> 0x9ffff */
 	ram_resource_kb(dev, idx++, 0, 0xa0000 / KiB);