diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 55b15b475..94e02c610 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -105,6 +105,7 @@ class CMainParams : public CChainParams {
         checkpointPubKey = "04c1e0b0db27b846cd9b8f151904f7edfc2dfaf6f062471f8f86fc23418e0a23f2551e34b02642c79bfeb75755d23d5194243b73318ce35eace6e6042ec399b37c";
         nNeoScryptHeight = 120000;
         nNeoScryptFork = 1414482565;
+        nBlockVersionChange = 840000;
         nDefaultPort = 42954;
         bnProofOfWorkLimit = ~uint256(0) >> 20;
         bnNeoScryptSwitch = ~uint256(0) >> 28;
@@ -178,6 +179,7 @@ class CTestNetParams : public CMainParams {
         vAlertPubKey = ParseHex("04e4f58b6a870d4ac13b35ca00f390c674561fea1c161b0c28b34c22ebb34afa5c8d874d12106c34a06c06d20a32d863079a4162003961a88bae4655ebd6a0440f");
         checkpointPubKey = "04b0c74b4334f0fd96f09070fbc28dc61a7dc1fbe8988ac98321f45fdd8ce8fed848f04ecaa398bfadb51b5f5adf706e9507f403ab5dce3c57bccf6c3a7db7e7a9";
         nNeoScryptHeight = 1;
+        nBlockVersionChange = 10;
         nDefaultPort = 52954;
         nEnforceBlockUpgradeMajority = 51;
         nRejectBlockOutdatedMajority = 75;
diff --git a/src/chainparams.h b/src/chainparams.h
index 678809f67..e96053077 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -47,6 +47,7 @@ class CChainParams
     const std::string CheckpointKey() const { return checkpointPubKey;}
     unsigned int NeoScryptFork() const { return nNeoScryptFork;}
     int NeoScryptHeight() const { return nNeoScryptHeight;}
+    int BlockVersionChange() const { return nBlockVersionChange;}
     int GetDefaultPort() const { return nDefaultPort; }
     const uint256& ProofOfWorkLimit() const { return bnProofOfWorkLimit; }
     const uint256& NeoScryptWorkLimit() const { return bnNeoScryptSwitch; }
@@ -93,6 +94,7 @@ class CChainParams
     std::string checkpointPubKey;
     unsigned int nNeoScryptFork;
     int nNeoScryptHeight;
+    int nBlockVersionChange;
     int nDefaultPort;
     uint256 bnProofOfWorkLimit;
     uint256 bnNeoScryptSwitch;
diff --git a/src/main.cpp b/src/main.cpp
index 478fbc5b8..b39e7859f 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1911,12 +1911,12 @@ void static UpdateTip(CBlockIndex *pindexNew) {
         const CBlockIndex* pindex = chainActive.Tip();
         for (int i = 0; i < 100 && pindex != NULL; i++)
         {
-            if (pindex->nVersion > CBlock::CURRENT_VERSION)
+            if (pindex->nVersion > CBlock::NEW_VERSION)
                 ++nUpgraded;
             pindex = pindex->pprev;
         }
         if (nUpgraded > 0)
-            LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, (int)CBlock::CURRENT_VERSION);
+            LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, (int)CBlock::NEW_VERSION);
         if (nUpgraded > 100/2)
         {
             // strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
diff --git a/src/miner.cpp b/src/miner.cpp
index 656be607b..9ac9f7d76 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -97,6 +97,10 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         return NULL;
     CBlock *pblock = &pblocktemplate->block; // pointer for convenience
 
+    // Set block version to 4 after BlockVersionChange
+    if (chainActive.Tip()->nHeight + 1 >= Params().BlockVersionChange())
+        pblock->nVersion = CBlockHeader::NEW_VERSION;
+
     // -regtest only: allow overriding block.nVersion with
     // -blockversion=N to test forking scenarios
     if (Params().MineBlocksOnDemand())
diff --git a/src/primitives/block.h b/src/primitives/block.h
index dc9c1a098..ec91c8f42 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -25,6 +25,7 @@ class CBlockHeader
 public:
     // header
     static const int32_t CURRENT_VERSION=2;
+    static const int32_t NEW_VERSION=4;
     int32_t nVersion;
     uint256 hashPrevBlock;
     uint256 hashMerkleRoot;