diff --git a/cores/esp8266/Arduino.h b/cores/esp8266/Arduino.h
index f507bef3b..257dc3767 100644
--- a/cores/esp8266/Arduino.h
+++ b/cores/esp8266/Arduino.h
@@ -20,18 +20,23 @@
 #ifndef Arduino_h
 #define Arduino_h
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include <stdlib.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdio.h>
 #include <string.h>
 #include <math.h>
 
 #include "binary.h"
 #include "pgmspace.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+
 
 void yield(void);
 
diff --git a/cores/esp8266/libc_replacements.c b/cores/esp8266/libc_replacements.c
index baeb63fee..7d6260d1e 100644
--- a/cores/esp8266/libc_replacements.c
+++ b/cores/esp8266/libc_replacements.c
@@ -159,6 +159,10 @@ char* ICACHE_FLASH_ATTR strncat(char * dest, const char * src, size_t n) {
     return dest;
 }
 
+char* ICACHE_FLASH_ATTR strtok(char * str, const char * delimiters) {
+    return strtok_r(str, delimiters, NULL);
+}
+
 char* ICACHE_FLASH_ATTR strtok_r(char * str, const char * delimiters, char ** temp) {
     static char * ret = NULL;
     char * start = NULL;