diff --git a/src/northbridge/intel/haswell/gma.c b/src/northbridge/intel/haswell/gma.c
index 325edbd..5d0e8e7 100644
--- a/src/northbridge/intel/haswell/gma.c
+++ b/src/northbridge/intel/haswell/gma.c
@@ -171,14 +171,14 @@
 u32 gtt_read(u32 reg)
 {
 	u32 val;
-	val = read32(gtt_res->base + reg);
+	val = read32(res2mmio(gtt_res, reg, 0));
 	return val;
 
 }
 
 void gtt_write(u32 reg, u32 data)
 {
-	write32(gtt_res->base + reg, data);
+	write32(res2mmio(gtt_res, reg, 0), data);
 }
 
 static inline void gtt_rmw(u32 reg, u32 andmask, u32 ormask)