diff --git a/src/keyb.h b/src/keyb.h
index 9546e73..b4fa826 100644
--- a/src/keyb.h
+++ b/src/keyb.h
@@ -79,6 +79,8 @@
 
 .- */
 
+#include "cpu.h"
+
 /*---------------------------------------------------------------------------
         Function prototypes
   ---------------------------------------------------------------------------*/
diff --git a/src/x_func.h b/src/x_func.h
index 059649f..80bdd11 100644
--- a/src/x_func.h
+++ b/src/x_func.h
@@ -72,6 +72,8 @@
 
 .- */
 
+#include "cpu.h"
+
 /*---------------------------------------------------------------------------
         Macro/Data type definitions - require cpu.h
   ---------------------------------------------------------------------------*/