diff --git a/src/TransactionFormats.h b/src/TransactionFormats.h
index db0d0f2b0..e3d30c3a4 100644
--- a/src/TransactionFormats.h
+++ b/src/TransactionFormats.h
@@ -21,6 +21,10 @@ struct TransactionFormat
 };
 
 const int32 TransactionMagic=0x54584E00;
+
+const int TransactionIVersion=0, TransactionISigningAccount=1, TransactionISequence=2;
+const int TransactionIType=3, TransactionIFee=4;
+
 const int TransactionMinLen=32;
 const int TransactionMaxLen=1048576;