diff --git a/src/mainboard/olpc/rev_a/auto.c b/src/mainboard/olpc/rev_a/auto.c
index 0c148b4f68..249df48814 100644
--- a/src/mainboard/olpc/rev_a/auto.c
+++ b/src/mainboard/olpc/rev_a/auto.c
@@ -153,7 +153,7 @@ static void main(unsigned long bist)
 	SystemPreInit();
 	msr_init();
 
-	w83627hf_enable_serial(SERIAL_DEV, TTYS0_BASE);
+	cs5536_setup_onchipuart();
 	uart_init();
 	console_init();
 
diff --git a/src/southbridge/amd/cs5536/cs5536_early_setup.c b/src/southbridge/amd/cs5536/cs5536_early_setup.c
index ff31f76235..99cc5d28c5 100644
--- a/src/southbridge/amd/cs5536/cs5536_early_setup.c
+++ b/src/southbridge/amd/cs5536/cs5536_early_setup.c
@@ -155,6 +155,15 @@ static void dummy(void)
 {
 }
 
+/* see page 412 of the cs5536 companion book */
+static int cs5536_setup_onchipuart(void) {
+	msr_t msr;
+	msr.lo = 2;
+	msr.hi = 0;
+	wrmsr(0x5160003a, msr);
+	wrmsr(0x5160003e, msr);
+}
+
 static int cs5536_early_setup(void)
 {
 	msr_t msr;