diff --git a/Thread.h b/Thread.h
index 1bd457a..b4ce55b 100644
--- a/Thread.h
+++ b/Thread.h
@@ -14,7 +14,12 @@
 #ifndef Thread_h
 #define Thread_h
 
-#include <Arduino.h>
+#if defined(ARDUINO) && ARDUINO >= 100
+	#include <Arduino.h>
+#else
+	#include <WProgram.h>
+#endif
+
 #include <inttypes.h>
 
 /*