diff --git a/arch/arm/src/stm32l4/stm32l4_serial.c b/arch/arm/src/stm32l4/stm32l4_serial.c
index 62b609b972c..15347627b70 100644
--- a/arch/arm/src/stm32l4/stm32l4_serial.c
+++ b/arch/arm/src/stm32l4/stm32l4_serial.c
@@ -269,7 +269,7 @@ static int  stm32l4serial_setup(FAR struct uart_dev_s *dev);
 static void stm32l4serial_shutdown(FAR struct uart_dev_s *dev);
 static int  stm32l4serial_attach(FAR struct uart_dev_s *dev);
 static void stm32l4serial_detach(FAR struct uart_dev_s *dev);
-static int  up_interrupt((int irq, FAR void *context, FAR void *arg);
+static int  up_interrupt(int irq, FAR void *context, FAR void *arg);
 static int  stm32l4serial_ioctl(FAR struct file *filep, int cmd,
                                 unsigned long arg);
 #ifndef SERIAL_HAVE_ONLY_DMA
@@ -1417,7 +1417,7 @@ static void stm32l4serial_detach(FAR struct uart_dev_s *dev)
  *
  ****************************************************************************/
 
-static int up_interrupt((int irq, FAR void *context, FAR void *arg)
+static int up_interrupt(int irq, FAR void *context, FAR void *arg)
 {
   FAR struct stm32l4_serial_s *priv = (FAR struct stm32l4_serial_s *)arg;
   int  passes;