diff --git a/arch/arm/mach-at91/pm_slowclock.S b/arch/arm/mach-at91/pm_slowclock.S
index a2cc49f96f61..8ab80e579be0 100644
--- a/arch/arm/mach-at91/pm_slowclock.S
+++ b/arch/arm/mach-at91/pm_slowclock.S
@@ -205,6 +205,7 @@ sdr_sr_done:
 	/* Turn off the main oscillator */
 	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
 	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
+	orr	tmp1, tmp1, #AT91_PMC_KEY
 	str	tmp1, [pmc, #AT91_CKGR_MOR]
 
 	/* Wait for interrupt */
@@ -213,6 +214,7 @@ sdr_sr_done:
 	/* Turn on the main oscillator */
 	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
 	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
+	orr	tmp1, tmp1, #AT91_PMC_KEY
 	str	tmp1, [pmc, #AT91_CKGR_MOR]
 
 	wait_moscrdy