diff --git a/lib/transaction/transaction.js b/lib/transaction/transaction.js
index 5dcbba0fe..b1a699bcf 100644
--- a/lib/transaction/transaction.js
+++ b/lib/transaction/transaction.js
@@ -11,6 +11,7 @@ var BufferReader = require('../encoding/bufferreader');
 var BufferWriter = require('../encoding/bufferwriter');
 var Hash = require('../crypto/hash');
 var Signature = require('../crypto/signature');
+var Sighash = require('./sighash');
 
 var Address = require('../address');
 var Unit = require('../unit');