diff --git a/cpu/ppc4xx/start.S b/cpu/ppc4xx/start.S
index a96083caa581cc10b357ac52d6c8a5aeab46c5b3..85660b40dcdf1212ed4d4ce9e7e55579a8361608 100644
--- a/cpu/ppc4xx/start.S
+++ b/cpu/ppc4xx/start.S
@@ -783,7 +783,7 @@ _start:
 	mtdcr	ocmdscr2, r3            /* Set Data Side */
 	mtdcr	ocmiscr2, r3            /* Set Instruction Side */
 	addis	r3,0,0x0800             /* OCM Data Parity Disable - 1 Wait State */
-	mtdcr	ocmdsisdpc,r4
+	mtdcr	ocmdsisdpc,r3
 
 	isync
 #else /* CONFIG_405EZ */