diff --git a/cores/esp8266/Arduino.h b/cores/esp8266/Arduino.h
index 31b6fc5d8..3060ba185 100644
--- a/cores/esp8266/Arduino.h
+++ b/cores/esp8266/Arduino.h
@@ -88,7 +88,7 @@ void yield(void);
 
 #define kBit (1024L)
 #define MBit (1024L*kBit)
-#define GBit (1024L*kBit)
+#define GBit (1024L*MBit)
 
 #define kB (1024L)
 #define MB (1024L*kB)