diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h
index 80aabd8..6b497aa 100644
--- a/src/cryptonote_config.h
+++ b/src/cryptonote_config.h
@@ -7,4 +7,5 @@ enum BLOB_TYPE {
   BLOB_TYPE_FORKNOTE1   = 1,
   BLOB_TYPE_FORKNOTE2   = 2,
   BLOB_TYPE_CRYPTONOTE2 = 3, // Masari
+  BLOB_TYPE_CRYPTONOTE_RYO = 4, // Ryo
 };
\ No newline at end of file
diff --git a/src/cryptonote_core/cryptonote_format_utils.cpp b/src/cryptonote_core/cryptonote_format_utils.cpp
index 0ceba8f..5db8bde 100644
--- a/src/cryptonote_core/cryptonote_format_utils.cpp
+++ b/src/cryptonote_core/cryptonote_format_utils.cpp
@@ -19,6 +19,7 @@ namespace cryptonote
   void get_transaction_prefix_hash(const transaction_prefix& tx, crypto::hash& h)
   {
     std::ostringstream s;
+    s << "ryo-currency";
     binary_archive<true> a(s);
     ::serialization::serialize(a, const_cast<transaction_prefix&>(tx));
     crypto::cn_fast_hash(s.str().data(), s.str().size(), h);