diff --git a/arch/powerpc/cpu/mpc8xx/cpu.c b/arch/powerpc/cpu/mpc8xx/cpu.c
index 1120fd7..9da73ac 100644
--- a/arch/powerpc/cpu/mpc8xx/cpu.c
+++ b/arch/powerpc/cpu/mpc8xx/cpu.c
@@ -36,7 +36,7 @@
 
 static int check_CPU(long clock, uint pvr, uint immr)
 {
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	uint k;
 	char buf[32];
 
@@ -237,8 +237,7 @@
  */
 unsigned long get_tbclk(void)
 {
-	uint immr = get_immr(0);	/* Return full IMMR contents */
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	ulong oscclk, factor, pll;
 
 	if (in_be32(&immap->im_clkrst.car_sccr) & SCCR_TBS)
diff --git a/arch/powerpc/cpu/mpc8xx/speed.c b/arch/powerpc/cpu/mpc8xx/speed.c
index fa8f87c..f8eb4a1 100644
--- a/arch/powerpc/cpu/mpc8xx/speed.c
+++ b/arch/powerpc/cpu/mpc8xx/speed.c
@@ -17,8 +17,7 @@
  */
 int get_clocks(void)
 {
-	uint immr = get_immr(0);	/* Return full IMMR contents */
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	uint sccr = in_be32(&immap->im_clkrst.car_sccr);
 	uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2);