diff --git a/arch/arm/mach-s3c2443/clock.c b/arch/arm/mach-s3c2443/clock.c
index a1a7176675b9904210545133303542e25d4636b6..38058af48972d7cf10409885b6e7578032a94d90 100644
--- a/arch/arm/mach-s3c2443/clock.c
+++ b/arch/arm/mach-s3c2443/clock.c
@@ -128,7 +128,7 @@ static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
 		unsigned long clkcon0;
 
 		clkcon0 = __raw_readl(S3C2443_CLKDIV0);
-		clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
+		clkcon0 &= ~S3C2443_CLKDIV0_ARMDIV_MASK;
 		clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT;
 		__raw_writel(clkcon0, S3C2443_CLKDIV0);
 	}