diff --git a/src/northbridge/intel/x4x/Kconfig b/src/northbridge/intel/x4x/Kconfig
index 711340d..99f6d79 100644
--- a/src/northbridge/intel/x4x/Kconfig
+++ b/src/northbridge/intel/x4x/Kconfig
@@ -37,4 +37,13 @@
 	int
 	default 4
 
+config FIXED_MCHBAR_MMIO_BASE
+	default 0xfed14000
+
+config FIXED_DMIBAR_MMIO_BASE
+	default 0xfed18000
+
+config FIXED_EPBAR_MMIO_BASE
+	default 0xfed19000
+
 endif