diff --git a/lib/ScriptInterpreter.js b/lib/ScriptInterpreter.js
index d5738b3f7..ac9912b34 100644
--- a/lib/ScriptInterpreter.js
+++ b/lib/ScriptInterpreter.js
@@ -8,11 +8,6 @@ var Util = require('../util');
 var Script = require('./Script');
 var Key = require('./Key');
 
-var SIGHASH_ALL = 1;
-var SIGHASH_NONE = 2;
-var SIGHASH_SINGLE = 3;
-var SIGHASH_ANYONECANPAY = 80;
-
 var intToBufferSM = Util.intToBufferSM
 var bufferSMToInt = Util.bufferSMToInt;
 
@@ -22,6 +17,11 @@ function ScriptInterpreter(opts) {
   this.disableUnsafeOpcodes = true;
 };
 
+var SIGHASH_ALL = ScriptInterpreter.SIGHASH_ALL = 1;
+var SIGHASH_NONE = ScriptInterpreter.SIGHASH_NONE = 2;
+var SIGHASH_SINGLE = ScriptInterpreter.SIGHASH_SINGLE = 3;
+var SIGHASH_ANYONECANPAY = ScriptInterpreter.SIGHASH_ANYONECANPAY = 0x80;
+
 ScriptInterpreter.prototype.eval = function eval(script, tx, inIndex, hashType, callback) {
   if ("function" !== typeof callback) {
     throw new Error("ScriptInterpreter.eval() requires a callback");
diff --git a/lib/Transaction.js b/lib/Transaction.js
index eeb1f8be1..067562473 100644
--- a/lib/Transaction.js
+++ b/lib/Transaction.js
@@ -299,15 +299,10 @@ Transaction.prototype.getAffectedKeys = function getAffectedKeys(txCache) {
 
 var OP_CODESEPARATOR = 171;
 
-var SIGHASH_ALL = 1;
-var SIGHASH_NONE = 2;
-var SIGHASH_SINGLE = 3;
-var SIGHASH_ANYONECANPAY = 0x80;
-
-Transaction.SIGHASH_ALL = SIGHASH_ALL;
-Transaction.SIGHASH_NONE = SIGHASH_NONE;
-Transaction.SIGHASH_SINGLE = SIGHASH_SINGLE;
-Transaction.SIGHASH_ANYONECANPAY = SIGHASH_ANYONECANPAY;
+var SIGHASH_ALL = Transaction.SIGHASH_ALL = ScriptInterpreter.SIGHASH_ALL;
+var SIGHASH_NONE = Transaction.SIGHASH_NONE = ScriptInterpreter.SIGHASH_NONE;
+var SIGHASH_SINGLE = Transaction.SIGHASH_SINGLE = ScriptInterpreter.SIGHASH_SINGLE;
+var SIGHASH_ANYONECANPAY = Transaction.SIGHASH_ANYONECANPAY = ScriptInterpreter.SIGHASH_ANYONECANPAY;
 
 var TransactionSignatureSerializer = function(txTo, scriptCode, nIn, nHashType) {
   this.txTo = txTo;
diff --git a/test/test.ScriptInterpreter.js b/test/test.ScriptInterpreter.js
index 78864feb7..0cac123b5 100644
--- a/test/test.ScriptInterpreter.js
+++ b/test/test.ScriptInterpreter.js
@@ -18,6 +18,16 @@ describe('ScriptInterpreter', function() {
     var si = new ScriptInterpreter();
     should.exist(si);
   });
+
+  describe('SIGHASH constants', function() {
+    it('should equal the values from bitcoin core', function() {
+      ScriptInterpreter.SIGHASH_ALL.should.equal(1);
+      ScriptInterpreter.SIGHASH_NONE.should.equal(2);
+      ScriptInterpreter.SIGHASH_SINGLE.should.equal(3);
+      ScriptInterpreter.SIGHASH_ANYONECANPAY.should.equal(0x80);
+    });
+  });
+
   var testScripts = function(data, valid) {
     data.forEach(function(datum) {
       if (datum.length < 2) throw new Error('Invalid test data');