diff --git a/src/DebugPrintMacros.h b/src/DebugPrintMacros.h
index 30ed706..43d8e15 100644
--- a/src/DebugPrintMacros.h
+++ b/src/DebugPrintMacros.h
@@ -1,6 +1,7 @@
 #ifndef _DEBUG_PRINT_MACROS_H
 #define _DEBUG_PRINT_MACROS_H
 // Some customizable print macros to suite the debug needs de jour.
+#include <Arduino.h>
 
 // Debug macros
 // #include <pgmspace.h>