diff --git a/src/main.c b/src/main.c
index c647cf9f..57d3bb55 100644
--- a/src/main.c
+++ b/src/main.c
@@ -51,6 +51,11 @@ static void SystemClock_Config(void);
 static USBD_GS_CAN_HandleTypeDef hGS_CAN;
 static USBD_HandleTypeDef hUSB = {0};
 
+void __weak _close(void) {}
+void __weak _lseek(void) {}
+void __weak _read(void) {}
+void __weak _write(void) {}
+
 int main(void)
 {
 	HAL_Init();