diff --git a/board/ALIENTEK_EXPLORER_STM32F407ZGT6/BSP/Src/stm32f4xx_it.c b/board/ALIENTEK_EXPLORER_STM32F407ZGT6/BSP/Src/stm32f4xx_it.c
index 3f0d31bc465f8c9abc9a85a977fa67cf88e69bc1..0d585b8d4ce324ef62fa7ec3734ef05d6321999d 100644
--- a/board/ALIENTEK_EXPLORER_STM32F407ZGT6/BSP/Src/stm32f4xx_it.c
+++ b/board/ALIENTEK_EXPLORER_STM32F407ZGT6/BSP/Src/stm32f4xx_it.c
@@ -236,13 +236,13 @@ void USART2_IRQHandler(void)
 
   /* USER CODE END USART2_IRQn 1 */
 	
- /* USER CODE BEGIN USART1_IRQn 0 */
+  /* USER CODE BEGIN USART1_IRQn 0 */
 	uint8_t tmp;
 	if(__HAL_UART_GET_FLAG(&huart2,UART_FLAG_PE))//???????
 	{
 		HAL_UART_Receive(&huart2,&tmp,1,1);
 	}
-        #ifdef USE_MODBUS
+        #if defined USE_MODBUS
 	else if(__HAL_UART_GET_FLAG(&huart2,UART_FLAG_RXNE)&&__HAL_UART_GET_IT_SOURCE(&huart2,UART_IT_RXNE))
 	{
 		prvvUARTRxISR();
@@ -276,7 +276,7 @@ void USART3_IRQHandler(void)
 void TIM6_DAC_IRQHandler(void)
 {
   /* USER CODE BEGIN TIM6_DAC_IRQn 0 */
-  #ifdef USE_MODBUS
+  #if defined USE_MODBUS
   prvvTIMERExpiredISR();
   #endif/* USE_MODBUS */
   /* USER CODE END TIM6_DAC_IRQn 0 */