diff --git a/include/reg.h b/include/reg.h
index b5dd528..c642947 100644
--- a/include/reg.h
+++ b/include/reg.h
@@ -41,4 +41,7 @@
 
 #define writeb(v, a) (*REG8(a) = (v))
 #define readb(a) (*REG8(a))
+
+#define writehw(v, a) (*REG16(a) = (v))
+#define readhw(a) (*REG16(a))
 #endif