diff --git a/src/main/scala/org/scalacoin/protocol/script/ScriptPubKey.scala b/src/main/scala/org/scalacoin/protocol/script/ScriptPubKey.scala
index e88f922d34..7a41856462 100644
--- a/src/main/scala/org/scalacoin/protocol/script/ScriptPubKey.scala
+++ b/src/main/scala/org/scalacoin/protocol/script/ScriptPubKey.scala
@@ -1,6 +1,7 @@
 package org.scalacoin.protocol.script
 
 import org.scalacoin.protocol.BitcoinAddress
+import org.scalacoin.script.ScriptToken
 
 /**
  * Created by chris on 12/26/15.
@@ -13,5 +14,5 @@ trait ScriptPubKey extends ScriptSignature {
 
 }
 
-case class ScriptPubKeyImpl(asm : String, hex : String, reqSigs : Int,
+case class ScriptPubKeyImpl(asm : List[ScriptToken], hex : String, reqSigs : Int,
   addressType : String, addresses : Seq[BitcoinAddress]) extends ScriptPubKey
diff --git a/src/main/scala/org/scalacoin/protocol/script/ScriptSignature.scala b/src/main/scala/org/scalacoin/protocol/script/ScriptSignature.scala
index 8fe1e1c305..ff132b9650 100644
--- a/src/main/scala/org/scalacoin/protocol/script/ScriptSignature.scala
+++ b/src/main/scala/org/scalacoin/protocol/script/ScriptSignature.scala
@@ -1,11 +1,13 @@
 package org.scalacoin.protocol.script
 
+import org.scalacoin.script.ScriptToken
+
 /**
  * Created by chris on 12/26/15.
  */
 trait ScriptSignature {
-  def asm : String
+  def asm : Seq[ScriptToken]
   def hex : String
 }
 
-case class ScriptSignatureImpl(asm : String, hex : String) extends ScriptSignature
\ No newline at end of file
+case class ScriptSignatureImpl(asm : Seq[ScriptToken], hex : String) extends ScriptSignature
\ No newline at end of file
diff --git a/src/main/scala/org/scalacoin/script/crypto/CryptoInterpreter.scala b/src/main/scala/org/scalacoin/script/crypto/CryptoInterpreter.scala
index dbe3940bbf..177d655725 100644
--- a/src/main/scala/org/scalacoin/script/crypto/CryptoInterpreter.scala
+++ b/src/main/scala/org/scalacoin/script/crypto/CryptoInterpreter.scala
@@ -29,15 +29,13 @@ trait CryptoInterpreter extends ScalacoinUtil {
    * @param script
    * @return
    */
-/*
-  def checkSig(inputScript : List[String], script : List[ScriptOperation]) : Boolean = {
+  def checkSig(inputScript : List[ScriptToken], script : List[ScriptToken], fullScript : List[ScriptToken]) : Boolean = {
     require(inputScript.size > 1, "We must have at least 2 inputs for our OP_CHECKSIG operation")
     require(script.headOption.isDefined && script.head == OP_CHECKSIG, "The top script stack element must be OP_CHECKSIG")
     val pubKey = inputScript.head
     val signature = inputScript(1)
     ???
   }
-*/
 
   /*def codeSeparator()*/
 
diff --git a/src/main/scala/org/scalacoin/script/interpreter/ScriptInterpreter.scala b/src/main/scala/org/scalacoin/script/interpreter/ScriptInterpreter.scala
index c8729f59bb..8e46af01f0 100644
--- a/src/main/scala/org/scalacoin/script/interpreter/ScriptInterpreter.scala
+++ b/src/main/scala/org/scalacoin/script/interpreter/ScriptInterpreter.scala
@@ -25,7 +25,9 @@ trait ScriptInterpreter extends CryptoInterpreter with StackInterpreter with Con
    */
 
   def run(inputScript : List[ScriptToken], outputScript : List[ScriptToken]) : Boolean = {
-
+    val fullInputScript = inputScript
+    val fullOutputScript = outputScript
+    val fullScript = inputScript ++ fullOutputScript
     @tailrec
     def loop(scripts : (List[ScriptToken], List[ScriptToken])) : Boolean = {
       val (inputScript,outputScript) = (scripts._1, scripts._2)
@@ -40,7 +42,7 @@ trait ScriptInterpreter extends CryptoInterpreter with StackInterpreter with Con
         case ScriptConstantImpl(x)  :: t => loop((ScriptConstantImpl(x) :: inputScript, t))
         //these cases result in our boolean result
         case OP_EQUALVERIFY :: t => equalVerify(inputScript,outputScript)
-        /*case OP_CHECKSIG :: t => checkSig(inputScript,outputScript)*/
+        case OP_CHECKSIG :: t => checkSig(inputScript,outputScript,fullScript)
       }
     }
 
diff --git a/src/test/scala/org/scalacoin/script/interpreter/ScriptInterpreterTest.scala b/src/test/scala/org/scalacoin/script/interpreter/ScriptInterpreterTest.scala
index 1273556e13..4c0205a16f 100644
--- a/src/test/scala/org/scalacoin/script/interpreter/ScriptInterpreterTest.scala
+++ b/src/test/scala/org/scalacoin/script/interpreter/ScriptInterpreterTest.scala
@@ -1,9 +1,10 @@
 package org.scalacoin.script.interpreter
 
 import org.scalacoin.script.bitwise.OP_EQUALVERIFY
-import org.scalacoin.script.{ ScriptOperation}
+import org.scalacoin.script.{ScriptToken, ScriptOperation}
 import org.scalacoin.script.crypto.{OP_CHECKSIG, OP_HASH160}
 import org.scalacoin.script.stack.OP_DUP
+import org.scalacoin.util.TestUtil
 import org.scalatest.{MustMatchers, FlatSpec}
 
 /**
@@ -13,17 +14,14 @@ class ScriptInterpreterTest extends FlatSpec with MustMatchers with ScriptInterp
 
 
 
-/*  "ScriptInterpreter" must "evaluate a valid script to true" in {
+  "ScriptInterpreter" must "evaluate a valid script to true" in {
     //this is in asm format, not hex
-    val inputScript =
-      List("3044022016ffdbb7c57634903c5e018fcfc48d59f4e37dc4bc3bbc9ba4e6ee39150bca030220119c2241a931819bc1a75d3596e4029d803d1cd6de123bf8a1a1a2c3665e1fac01",
-        "02af7dad03e682fcd0427b5c24140c220ac9d8abe286c15f8cf5bf77eed19c3652")
+    val inputScript = TestUtil.p2pkhInputScriptAsm
     //this is asm format, not hex
-    val outputScript : List[ScriptOperation] =
-      List(OP_DUP,OP_HASH160,ConstantImpl("e2e7c1ab3f807151e832dd1accb3d4f5d7d19b4b"),OP_EQUALVERIFY, OP_CHECKSIG)
+    val outputScript : List[ScriptToken] = TestUtil.p2pkhOutputScriptAsm
     val result = run(inputScript, outputScript)
     result must be (true)
-  }*/
+  }
 
 
 }