diff --git a/arch/arm/src/stm32/stm32_serial.c b/arch/arm/src/stm32/stm32_serial.c
index e1d6e45938..01c519b399 100644
--- a/arch/arm/src/stm32/stm32_serial.c
+++ b/arch/arm/src/stm32/stm32_serial.c
@@ -1218,7 +1218,9 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 {
   struct inode      *inode = filep->f_inode;
   struct uart_dev_s *dev   = inode->i_private;
+#ifdef CONFIG_SERIAL_TERMIOS
   struct up_dev_s   *priv  = (struct up_dev_s*)dev->priv;
+#endif
   int                ret    = OK;
 
   switch (cmd)