diff --git a/cpu/arm920t/s3c24x0/serial.c b/cpu/arm920t/s3c24x0/serial.c
index ba60ad1..ff7e0e5 100644
--- a/cpu/arm920t/s3c24x0/serial.c
+++ b/cpu/arm920t/s3c24x0/serial.c
@@ -114,6 +114,13 @@ void serial_setbrg(void)
 static int serial_init_dev(const int dev_index)
 {
 	S3C24X0_UART * const uart = S3C24X0_GetBase_UART(dev_index);
+	S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
+
+	if (dev_index > 2)
+		return -ENODEV;
+
+	/* Clock enable */
+	clk_power-> CLKCON |= (1 << 10 + dev_index);
 
 	/* FIFO enable, Tx/Rx FIFO clear */
 	uart->UFCON = 0x07;