diff --git a/src/main.cpp b/src/main.cpp
index a6fd6368b..80f13cb5d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4186,7 +4186,7 @@ public:
     }
 };
 
-CBlockTemplate* CreateNewBlock(CScript& scriptPubKeyIn)
+CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
 {
     // Create new block
     auto_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
diff --git a/src/main.h b/src/main.h
index 35c38a055..015cf263f 100644
--- a/src/main.h
+++ b/src/main.h
@@ -157,7 +157,7 @@ void ThreadScriptCheck();
 /** Run the miner threads */
 void GenerateBitcoins(bool fGenerate, CWallet* pwallet);
 /** Generate a new block, without valid proof-of-work */
-CBlockTemplate* CreateNewBlock(CScript& scriptPubKeyIn);
+CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn);
 CBlockTemplate* CreateNewBlockWithKey(CReserveKey& reservekey);
 /** Modify the extranonce in a block */
 void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce);