diff --git a/const.hpp b/const.hpp
index 5169987..1fc24cc 100644
--- a/const.hpp
+++ b/const.hpp
@@ -19,6 +19,7 @@
 using ECCOffset = uint16_t;
 using ECCLength = uint16_t;
 using LE2ByteData = uint16_t;
+using DataOffset = uint16_t;
 
 static constexpr auto MAC_ADDRESS_LEN_BYTES = 6;
 static constexpr auto LAST_KW = "PF";