diff --git a/src/script.cpp b/src/script.cpp
index 34872808..d0fb8303 100644
--- a/src/script.cpp
+++ b/src/script.cpp
@@ -1525,7 +1525,7 @@ bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const C
 }
 
 
-bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType, CScript scriptPrereq)
+bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType)
 {
     assert(nIn < txTo.vin.size());
     CTxIn& txin = txTo.vin[nIn];
@@ -1534,18 +1534,15 @@ bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CTrans
 
     // Leave out the signature from the hash, since a signature can't sign itself.
     // The checksig op will also drop the signatures from its hash.
-    uint256 hash = SignatureHash(scriptPrereq + txout.scriptPubKey, txTo, nIn, nHashType);
+    uint256 hash = SignatureHash(txout.scriptPubKey, txTo, nIn, nHashType);
 
     if (!Solver(keystore, txout.scriptPubKey, hash, nHashType, txin.scriptSig))
         return false;
 
-    txin.scriptSig = scriptPrereq + txin.scriptSig;
-
     // Test solution
     int nUnused = 0;
-    if (scriptPrereq.empty())
-        if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, nUnused, 0, true))
-            return false;
+    if (!VerifyScript(txin.scriptSig, txout.scriptPubKey, txTo, nIn, nUnused, 0, true))
+        return false;
 
     return true;
 }
diff --git a/src/script.h b/src/script.h
index 0080f5b7..64171c71 100644
--- a/src/script.h
+++ b/src/script.h
@@ -574,7 +574,7 @@ bool IsStandard(const CScript& scriptPubKey);
 bool IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
 bool ExtractAddress(const CScript& scriptPubKey, CBitcoinAddress& addressRet);
 bool ExtractAddresses(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CBitcoinAddress>& addressRet, int& nRequiredRet);
-bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL, CScript scriptPrereq=CScript());
+bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
 bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, int& nSigOpCountRet, int nHashType=0, bool fStrictOpEval=true);
 
 #endif