diff --git a/arch/arm/src/lpc31xx/lpc31_serial.c b/arch/arm/src/lpc31xx/lpc31_serial.c
index 691e2449d05..099fd1dfde9 100644
--- a/arch/arm/src/lpc31xx/lpc31_serial.c
+++ b/arch/arm/src/lpc31xx/lpc31_serial.c
@@ -89,7 +89,7 @@ static int  up_attach(struct uart_dev_s *dev);
 static void up_detach(struct uart_dev_s *dev);
 static int  up_interrupt(int irq, void *context, FAR void *arg);
 static int  up_ioctl(struct file *filep, int cmd, unsigned long arg);
-static int  up_receive(struct uart_dev_s *dev, uint32_t *status);
+static int  up_receive(struct uart_dev_s *dev, unsigned int *status);
 static void up_rxint(struct uart_dev_s *dev, bool enable);
 static bool up_rxavailable(struct uart_dev_s *dev);
 static void up_send(struct uart_dev_s *dev, int ch);
@@ -640,7 +640,7 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
  *
  ****************************************************************************/
 
-static int up_receive(struct uart_dev_s *dev, uint32_t *status)
+static int up_receive(struct uart_dev_s *dev, unsigned int *status)
 {
   uint32_t rbr;