diff --git a/stm32/f103c8t6/stm32f1xx_hal_uart.c b/stm32/f103c8t6/stm32f1xx_hal_uart.c
index 67de556..06fbd4d 100644
--- a/stm32/f103c8t6/stm32f1xx_hal_uart.c
+++ b/stm32/f103c8t6/stm32f1xx_hal_uart.c
@@ -686,7 +686,7 @@ HAL_StatusTypeDef HAL_MultiProcessor_Init(UART_HandleTypeDef *huart, uint8_t Add
   return HAL_OK;
 }
 
-volatile uint32_t v;
+volatile uint32_t _checkinter_count;
 
 static void
 checkinter(UART_HandleTypeDef *huart)
@@ -694,7 +694,7 @@ checkinter(UART_HandleTypeDef *huart)
 
 #if 1
 	if (huart->ReceptionType == 0 && huart->Instance->CR1 & 0x10) {
-		for(;;v++);
+		for(;;_checkinter_count++);
 	}
 #endif
 }