diff --git a/src/transaction.js b/src/transaction.js
index d80966b..0ed10c2 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -9,11 +9,11 @@ var ECKey = require('./eckey')
 var ECSignature = require('./ecsignature')
 var Script = require('./script')
 
-var DEFAULT_SEQUENCE = 0xffffffff
-var SIGHASH_ALL = 0x01
-var SIGHASH_NONE = 0x02
-var SIGHASH_SINGLE = 0x03
-var SIGHASH_ANYONECANPAY = 0x80
+Transaction.DEFAULT_SEQUENCE = 0xffffffff
+Transaction.SIGHASH_ALL = 0x01
+Transaction.SIGHASH_NONE = 0x02
+Transaction.SIGHASH_SINGLE = 0x03
+Transaction.SIGHASH_ANYONECANPAY = 0x80
 
 function Transaction() {
   this.version = 1
@@ -33,7 +33,7 @@ function Transaction() {
  * Note that this method does not sign the created input.
  */
 Transaction.prototype.addInput = function(tx, index, sequence) {
-  if (sequence == undefined) sequence = DEFAULT_SEQUENCE
+  if (sequence == undefined) sequence = Transaction.DEFAULT_SEQUENCE
 
   var hash
 
@@ -175,15 +175,15 @@ Transaction.prototype.hashForSignature = function(prevOutScript, inIndex, hashTy
   txTmp.ins[inIndex].script = hashScript
 
   var hashTypeModifier = hashType & 0x1f
-  if (hashTypeModifier === SIGHASH_NONE) {
+  if (hashTypeModifier === Transaction.SIGHASH_NONE) {
     assert(false, 'SIGHASH_NONE not yet supported')
 
-  } else if (hashTypeModifier === SIGHASH_SINGLE) {
+  } else if (hashTypeModifier === Transaction.SIGHASH_SINGLE) {
     assert(false, 'SIGHASH_SINGLE not yet supported')
 
   }
 
-  if (hashType & SIGHASH_ANYONECANPAY) {
+  if (hashType & Transaction.SIGHASH_ANYONECANPAY) {
     assert(false, 'SIGHASH_ANYONECANPAY not yet supported')
   }
 
@@ -307,7 +307,7 @@ Transaction.prototype.sign = function(index, privKey, hashType) {
 }
 
 Transaction.prototype.signInput = function(index, prevOutScript, privKey, hashType) {
-  hashType = hashType || SIGHASH_ALL
+  hashType = hashType || Transaction.SIGHASH_ALL
 
   var hash = this.hashForSignature(prevOutScript, index, hashType)
   var signature = privKey.sign(hash)
diff --git a/test/transaction.js b/test/transaction.js
index 6ac97f3..0288ed7 100644
--- a/test/transaction.js
+++ b/test/transaction.js
@@ -93,7 +93,7 @@ describe('Transaction', function() {
       var tx = new Transaction()
       tx.addInput(prevTxHash, 0)
 
-      assert.equal(tx.ins[0].sequence, 0xffffffff)
+      assert.equal(tx.ins[0].sequence, Transaction.DEFAULT_SEQUENCE)
     })
 
     fixtures.valid.forEach(function(f) {