diff --git a/esp8266/modpybi2c.c b/esp8266/modpybi2c.c
index f50038f1be..1337fe2b8a 100644
--- a/esp8266/modpybi2c.c
+++ b/esp8266/modpybi2c.c
@@ -29,6 +29,7 @@
 #include <string.h>
 
 #include "ets_sys.h"
+#include "etshal.h"
 #include "osapi.h"
 #include "gpio.h"