diff --git a/os/esptool.py b/os/esptool.py
index 6a9a97f..72fc3dc 100755
--- a/os/esptool.py
+++ b/os/esptool.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ESP8266 & ESP32 family ROM Bootloader Utility
 # Copyright (C) 2014-2016 Fredrik Ahlberg, Angus Gratton, Espressif Systems (Shanghai) PTE LTD, other contributors as noted.