diff --git a/src/northbridge/intel/ironlake/acpi/hostbridge.asl b/src/northbridge/intel/ironlake/acpi/hostbridge.asl
index d6a2cf8..62ca81a 100644
--- a/src/northbridge/intel/ironlake/acpi/hostbridge.asl
+++ b/src/northbridge/intel/ironlake/acpi/hostbridge.asl
@@ -48,7 +48,7 @@
 	Name (CTCD, 1)		/* CTDP Down Select */
 	Name (CTCU, 2)		/* CTDP Up Select */
 
-	OperationRegion (MCHB, SystemMemory, DEFAULT_MCHBAR, 0x8000)
+	OperationRegion (MCHB, SystemMemory, CONFIG_FIXED_MCHBAR_MMIO_BASE, 0x8000)
 	Field (MCHB, DWordAcc, Lock, Preserve)
 	{
 		Offset (0x5930),