1 files changed, 1 insertions, 0 deletions
diff --git a/cores/arduino/WProgram.h b/cores/arduino/WProgram.h
index 39dc611..81a1a9b 100755
--- a/cores/arduino/WProgram.h
+++ b/cores/arduino/WProgram.h
@@ -10,6 +10,7 @@
 #include "wiring.h"
 
 #ifdef __cplusplus
+#include "WString.h"
 #include "HardwareSerial.h"
 
 uint16_t makeWord(uint16_t w);