diff --git a/hardware/cores/arduino/wiring.h b/hardware/cores/arduino/wiring.h
index 21d62c71c..619e695f1 100755
--- a/hardware/cores/arduino/wiring.h
+++ b/hardware/cores/arduino/wiring.h
@@ -32,6 +32,10 @@
 extern "C"{
 #endif
 
+#ifndef ARDUINO
+#define ARDUINO 16
+#endif
+
 #define HIGH 0x1
 #define LOW  0x0