diff --git a/hardware/tools/esp8266/sdk/include/c_types.h b/hardware/tools/esp8266/sdk/include/c_types.h
index c9493cbb0f..b5385126c4 100644
--- a/hardware/tools/esp8266/sdk/include/c_types.h
+++ b/hardware/tools/esp8266/sdk/include/c_types.h
@@ -76,10 +76,7 @@ typedef enum {
 #endif /* ICACHE_FLASH */
 
 #ifndef __cplusplus
-typedef unsigned char   bool;
 #define BOOL            bool
-#define true            (1)
-#define false           (0)
 #define TRUE            true
 #define FALSE           false