diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index ab449f3e7..d37696199 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -51,6 +51,7 @@ BITCOIN_TESTS =\
   test/key_tests.cpp \
   test/main_tests.cpp \
   test/miner_tests.cpp \
+  test/blockv2_tests.cpp \
   test/mruset_tests.cpp \
   test/multisig_tests.cpp \
   test/netbase_tests.cpp \
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 179db5a81..d924a6a2b 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -214,8 +214,50 @@ public:
 };
 static CRegTestParams regTestParams;
 
+//
+// Regression test
+//
+class CUnitTestParams : public CMainParams, public CModifiableParams {
+public:
+    CUnitTestParams() {
+        networkID = CBaseChainParams::UNITTEST;
+        strNetworkID = "unittest";
+        nDefaultPort = 18445;
+        vFixedSeeds.clear();
+        vSeeds.clear();  // Regtest mode doesn't have any DNS seeds.
+
+        fRequireRPCPassword = false;
+        fMiningRequiresPeers = false;
+        fDefaultCheckMemPool = true;
+        fAllowMinDifficultyBlocks = false;
+        fMineBlocksOnDemand = true;
+        fSkipProofOfWorkCheck = false;
+    }
+    virtual bool SkipProofOfWorkCheck() const { return fSkipProofOfWorkCheck; }
+protected:
+    bool fSkipProofOfWorkCheck;
+public:
+    // Published setters to allow changing values in unit test cases
+    virtual void setSubsidyHalvingInterval(int anSubsidyHalvingInterval)  { nSubsidyHalvingInterval=anSubsidyHalvingInterval; }
+    virtual void setEnforceBlockUpgradeMajority(int anEnforceBlockUpgradeMajority)  { nEnforceBlockUpgradeMajority=anEnforceBlockUpgradeMajority; }
+    virtual void setRejectBlockOutdatedMajority(int anRejectBlockOutdatedMajority)  { nRejectBlockOutdatedMajority=anRejectBlockOutdatedMajority; }
+    virtual void setToCheckBlockUpgradeMajority(int anToCheckBlockUpgradeMajority)  { nToCheckBlockUpgradeMajority=anToCheckBlockUpgradeMajority; }
+    virtual void setDefaultCheckMemPool(bool aDefaultCheckMemPool)  { fDefaultCheckMemPool=aDefaultCheckMemPool; }
+    virtual void setAllowMinDifficultyBlocks(bool aAllowMinDifficultyBlocks) {  fAllowMinDifficultyBlocks=aAllowMinDifficultyBlocks; }
+    virtual void setSkipProofOfWorkCheck(bool aSkipProofOfWorkCheck) { fSkipProofOfWorkCheck = aSkipProofOfWorkCheck; }
+};
+static CUnitTestParams unitTestParams;
+
+
 static CChainParams *pCurrentParams = 0;
 
+CModifiableParams *ModifiableParams()
+{
+   assert(pCurrentParams);
+   assert(pCurrentParams==&unitTestParams);
+   return (CModifiableParams*)&unitTestParams;
+}
+
 const CChainParams &Params() {
     assert(pCurrentParams);
     return *pCurrentParams;
@@ -229,6 +271,8 @@ CChainParams &Params(CBaseChainParams::Network network) {
             return testNetParams;
         case CBaseChainParams::REGTEST:
             return regTestParams;
+        case CBaseChainParams::UNITTEST:
+            return unitTestParams;
         default:
             assert(false && "Unimplemented network");
             return mainParams;
diff --git a/src/chainparams.h b/src/chainparams.h
index e5dfc87c6..171a590a5 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -61,6 +61,8 @@ public:
     bool DefaultCheckMemPool() const { return fDefaultCheckMemPool; }
     /* Allow mining of a min-difficulty block */
     bool AllowMinDifficultyBlocks() const { return fAllowMinDifficultyBlocks; }
+    /* Skip proof-of-work check: allow mining of any difficulty block */
+    virtual bool SkipProofOfWorkCheck() const { return false; }
     /* Make standard checks */
     bool RequireStandard() const { return fRequireStandard; }
     int64_t TargetTimespan() const { return nTargetTimespan; }
@@ -105,6 +107,24 @@ protected:
     bool fMineBlocksOnDemand;
 };
 
+/** Modifiable parameters interface is used by test cases to adapt the parameters in order
+*** to test specific features more easily. Test cases should always restore the previous
+*** values after finalization.
+**/
+
+class CModifiableParams {
+public:
+    // Published setters to allow changing values in unit test cases
+    virtual void setSubsidyHalvingInterval(int anSubsidyHalvingInterval) =0;
+    virtual void setEnforceBlockUpgradeMajority(int anEnforceBlockUpgradeMajority)=0;
+    virtual void setRejectBlockOutdatedMajority(int anRejectBlockOutdatedMajority)=0;
+    virtual void setToCheckBlockUpgradeMajority(int anToCheckBlockUpgradeMajority)=0;
+    virtual void setDefaultCheckMemPool(bool aDefaultCheckMemPool)=0;
+    virtual void setAllowMinDifficultyBlocks(bool aAllowMinDifficultyBlocks)=0;
+    virtual void setSkipProofOfWorkCheck(bool aSkipProofOfWorkCheck)=0;
+};
+
+
 /**
  * Return the currently selected parameters. This won't change after app startup
  * outside of the unit tests.
@@ -114,6 +134,9 @@ const CChainParams &Params();
 /** Return parameters for the given network. */
 CChainParams &Params(CBaseChainParams::Network network);
 
+/** Get modifyable network parameters (UNITTEST only) */
+CModifiableParams *ModifiableParams();
+
 /** Sets the params returned by Params() to those for the given network. */
 void SelectParams(CBaseChainParams::Network network);
 
diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
index 98bb5b855..e9d63197b 100644
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -57,6 +57,20 @@ public:
 };
 static CBaseRegTestParams regTestParams;
 
+//
+// Unit test
+//
+class CBaseUnitTestParams : public CBaseMainParams
+{
+public:
+    CBaseUnitTestParams()
+    {
+        networkID = CBaseChainParams::UNITTEST;
+        strDataDir = "unittest";
+    }
+};
+static CBaseUnitTestParams unitTestParams;
+
 static CBaseChainParams* pCurrentBaseParams = 0;
 
 const CBaseChainParams& BaseParams()
@@ -77,6 +91,9 @@ void SelectBaseParams(CBaseChainParams::Network network)
     case CBaseChainParams::REGTEST:
         pCurrentBaseParams = &regTestParams;
         break;
+    case CBaseChainParams::UNITTEST:
+        pCurrentBaseParams = &unitTestParams;
+        break;
     default:
         assert(false && "Unimplemented network");
         return;
diff --git a/src/chainparamsbase.h b/src/chainparamsbase.h
index c054f03f1..cc154cf50 100644
--- a/src/chainparamsbase.h
+++ b/src/chainparamsbase.h
@@ -19,6 +19,7 @@ public:
         MAIN,
         TESTNET,
         REGTEST,
+        UNITTEST,
 
         MAX_NETWORK_TYPES
     };
diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index c41deea7c..9a6bc05e6 100644
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -88,6 +88,8 @@ namespace Checkpoints {
             return dataTestnet;
         else if (Params().NetworkID() == CBaseChainParams::MAIN)
             return data;
+        else if (Params().NetworkID() == CBaseChainParams::UNITTEST) // UnitTest share the same checkpoints as MAIN
+            return data;
         else
             return dataRegtest;
     }
diff --git a/src/main.cpp b/src/main.cpp
index 9a4271eda..4bd8fd6e3 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2304,6 +2304,7 @@ bool AcceptBlockHeader(CBlockHeader& block, CValidationState& state, CBlockIndex
         nHeight = pindexPrev->nHeight+1;
 
         // Check proof of work
+        if (!Params().SkipProofOfWorkCheck())
         if (block.nBits != GetNextWorkRequired(pindexPrev, &block))
             return state.DoS(100, error("AcceptBlock() : incorrect proof of work"),
                              REJECT_INVALID, "bad-diffbits");
diff --git a/src/pow.cpp b/src/pow.cpp
index 893f6c18b..d50222849 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -81,6 +81,10 @@ bool CheckProofOfWork(uint256 hash, unsigned int nBits)
     bool fNegative;
     bool fOverflow;
     uint256 bnTarget;
+
+    if (Params().SkipProofOfWorkCheck())
+       return true;
+
     bnTarget.SetCompact(nBits, &fNegative, &fOverflow);
 
     // Check range
diff --git a/src/test/base58_tests.cpp b/src/test/base58_tests.cpp
index 58fffb6df..c298c805d 100644
--- a/src/test/base58_tests.cpp
+++ b/src/test/base58_tests.cpp
@@ -175,7 +175,7 @@ BOOST_AUTO_TEST_CASE(base58_keys_valid_parse)
             BOOST_CHECK_MESSAGE(!secret.IsValid(), "IsValid pubkey as privkey:" + strTest);
         }
     }
-    SelectParams(CBaseChainParams::MAIN);
+    SelectParams(CBaseChainParams::UNITTEST);
 }
 
 // Goal: check that generated keys match test vectors
@@ -243,7 +243,7 @@ BOOST_AUTO_TEST_CASE(base58_keys_valid_gen)
     CTxDestination nodest = CNoDestination();
     BOOST_CHECK(!dummyAddr.Set(nodest));
 
-    SelectParams(CBaseChainParams::MAIN);
+    SelectParams(CBaseChainParams::UNITTEST);
 }
 
 // Goal: check that base58 parsing code is robust against a variety of corrupted data
diff --git a/src/test/blockv2_tests.cpp b/src/test/blockv2_tests.cpp
new file mode 100644
index 000000000..0d59c8761
--- /dev/null
+++ b/src/test/blockv2_tests.cpp
@@ -0,0 +1,232 @@
+// Copyright (c) 2011-2014 The Bitcoin Core developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "main.h"
+#include "miner.h"
+#include "uint256.h"
+#include "util.h"
+
+#include <boost/test/unit_test.hpp>
+
+// Tests the majority rule which states that after 1000 v2 blocks no v1 block can go
+BOOST_AUTO_TEST_SUITE(blockv2_tests)
+
+static CScript scriptPubKey = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
+
+static void SetEmptyBlock(CBlock * pblock)
+{
+        pblock->nVersion = 2;
+        pblock->nTime = chainActive.Tip()->GetMedianTimePast()+1;
+        pblock->nNonce = 0;
+}
+
+static void SetBlockDefaultAttributesAndHeight(CBlock * pblock,bool addHeight,int difValue)
+{
+        SetEmptyBlock(pblock);
+
+        // Add the coinbase
+        CMutableTransaction txCoinbase(pblock->vtx[0]);
+
+        if (addHeight)
+            txCoinbase.vin[0].scriptSig = (CScript() << (chainActive.Height()+1+difValue) << 0);
+            else
+            txCoinbase.vin[0].scriptSig = (CScript() << difValue << 0); // At least size 2, this is a protocol spec
+
+        txCoinbase.vout[0].scriptPubKey = CScript();
+        pblock->vtx[0] = CTransaction(txCoinbase);
+        pblock->hashMerkleRoot = pblock->BuildMerkleTree();
+}
+
+void CheckSubsidyHalving(CBlockTemplate * &pblocktemplate, CBlock * &pblock)
+{
+    if ((chainActive.Height()+1) % Params().SubsidyHalvingInterval() == 0)
+        {
+            // The RegTest network has a low subsidy halving interval (150) so
+            // we must recompute the coinbase subsidy if we reach the boundary.
+
+            // preserve parent hash
+            uint256 prevParent = pblock->hashPrevBlock;
+            delete pblocktemplate;
+            pblocktemplate = CreateNewBlock(scriptPubKey);
+            pblock = &pblocktemplate->block; // pointer for convenience
+            pblock->hashPrevBlock = prevParent;
+        }
+}
+
+void Blockv2test()
+{
+    assert(Params().NetworkID() == CBaseChainParams::UNITTEST);
+    ModifiableParams()->setSkipProofOfWorkCheck(true);
+
+    // We don't know the state of the block-chain here: it depends on which other tests are run before this test.
+    // See https://github.com/bitcoin/bitcoin/pull/4688 for a patch that allows the re-creation of the block-chain
+    // for each testcase that requires it.
+
+    // If miner_tests.cpp is run before, the chain will be 100 blocks long, and all of them will be v1
+
+
+    LogPrintf("Blockv2test testcase starts\n");
+
+    CBlockTemplate *pblocktemplate;
+    CScript script;
+    uint256 hash;
+    int PreviousHeight;
+
+
+    LOCK(cs_main);
+
+
+    // Simple block creation, nothing special yet.
+    pblocktemplate = CreateNewBlock(scriptPubKey);
+    CBlock *pblock = &pblocktemplate->block; // pointer for convenience
+
+    LogPrintf("Blockv2test block v1 add begin\n");
+    // First create a block v1, check that it is accepted. The block has an invalid height
+    SetBlockDefaultAttributesAndHeight(pblock,false,5000);
+    pblock->nVersion = 1;
+    CValidationState state1;
+    PreviousHeight = chainActive.Height();
+    BOOST_CHECK(ProcessBlock(state1, NULL, pblock));
+    BOOST_CHECK(state1.IsValid());
+    BOOST_CHECK((PreviousHeight+1) == chainActive.Height()); // to differentiate from orphan blocks, which also get accepted in ProcessBlock()
+    pblock->hashPrevBlock = pblock->GetHash(); // update parent
+
+
+    // Now create exactly 1000 blocks v2
+
+    // First check that the supermajority threshold is exactly 1000 blocks
+    BOOST_CHECK(Params().ToCheckBlockUpgradeMajority()==1000);  //
+    BOOST_CHECK(Params().EnforceBlockUpgradeMajority()==750);
+    BOOST_CHECK(Params().RejectBlockOutdatedMajority()==950);
+
+    // Over the last 1000 blocks, 750 blocks must be v2 to switch to v2-only mode.
+    // Here we're testing only the last 750, not any subset.
+
+    LogPrintf("Blockv2test BIP30 repetition begin\n");
+
+    // First, if we try to add a block v2 with the same coinbase tx, we should get
+    // "bad-txns-BIP30" because the coinbase tx has the same hash as the previous.
+    // Unluckily, even if ConnectBlock returns a "bad-txns-BIP30", ActivateBestChainStep clears
+    // the state, so we get true here and the "bad-txns-BIP30" reason is lost.
+    // We verify instead that the chain height has not been incremented.
+
+    CValidationState state7;
+    PreviousHeight = chainActive.Height();
+    CheckSubsidyHalving(pblocktemplate,pblock);
+    SetBlockDefaultAttributesAndHeight(pblock,false,5000); //
+    pblock->nVersion = 2;
+    BOOST_CHECK(ProcessBlock(state7, NULL, pblock)); // should we care about the return value?
+    BOOST_CHECK(state7.IsValid());
+    BOOST_CHECK(PreviousHeight == chainActive.Height()); // we check the block has not been added.
+
+    LogPrintf("Blockv2test 750 v2 blocks  begin\n");
+    for (int i=0;i<750;i++)
+    {
+
+        LogPrintf("Blockv2test block %d begin\n",i);
+
+        CheckSubsidyHalving(pblocktemplate,pblock);
+
+        // We add a value to the height to make is NOT equal to the actual height.
+        SetBlockDefaultAttributesAndHeight(pblock,true,1000); // blocks version 2 without height are allowed! for only 750 blocks
+        pblock->nVersion = 2;
+        CValidationState state;
+
+        PreviousHeight = chainActive.Height();
+        BOOST_CHECK(ProcessBlock(state, NULL, pblock));
+        BOOST_CHECK(state.IsValid());
+        BOOST_CHECK((PreviousHeight+1) == chainActive.Height()); // to differentiate from orphan blocks, which also get accepted in ProcessBlock()
+        pblock->hashPrevBlock = pblock->GetHash(); // update parent
+    }
+
+    LogPrintf("Blockv2test v2 without height rejected begin\n");
+
+    // Now we try to add a block v2, with an invalid height and it should be rejected. We use 2000 because is not in the range [1000..1750].
+    CheckSubsidyHalving(pblocktemplate,pblock);
+    SetBlockDefaultAttributesAndHeight(pblock,true,2000); //
+    pblock->nVersion = 2;
+    CValidationState state0;
+    BOOST_CHECK(ProcessBlock(state0, NULL, pblock)==false);
+    BOOST_CHECK(!state0.IsValid());
+    BOOST_CHECK(state0.GetRejectReason()=="bad-cb-height");
+    // Do not update parent since block has failed
+
+    LogPrintf("Blockv2test v2 with height accepted begin\n");
+
+
+    // Now we add a block with height, must be ok.
+    for (int i=0;i<200;i++)
+    {
+
+        LogPrintf("Blockv2test v2block %d begin\n",i);
+        CheckSubsidyHalving(pblocktemplate,pblock);
+        SetBlockDefaultAttributesAndHeight(pblock,true,0);
+        pblock->nVersion = 2;
+        CValidationState state;
+        PreviousHeight = chainActive.Height();
+        BOOST_CHECK(ProcessBlock(state, NULL, pblock));
+        BOOST_CHECK(state.IsValid());
+        BOOST_CHECK((PreviousHeight+1) == chainActive.Height()); // to differentiate from orphan blocks, which also get accepted in ProcessBlock()
+
+        pblock->hashPrevBlock = pblock->GetHash(); // update parent
+    }
+
+
+    LogPrintf("Blockv2test block v1 rejected\n");
+    // Now we add 200 additional blocks, until we get 950 (the threshold were v1 blocks are not accepted anymore)
+    // Now we try to add a block v1, it should be rejected, even if it hash the height field
+    CheckSubsidyHalving(pblocktemplate,pblock);
+    SetBlockDefaultAttributesAndHeight(pblock,true,0);
+    pblock->nVersion = 1;
+    CValidationState state2;
+    BOOST_CHECK(ProcessBlock(state2, NULL, pblock)==false);
+    BOOST_CHECK(!state2.IsValid());
+    BOOST_CHECK(state2.GetRejectReason()=="bad-version");
+    // Do not update parent since block has failed
+
+
+
+    // Some other missing tests, added here as bonus...
+
+    // Block time too old check
+    CheckSubsidyHalving(pblocktemplate,pblock);
+    SetBlockDefaultAttributesAndHeight(pblock,true,0);
+    pblock->nVersion = 2;
+    pblock->nTime = chainActive.Tip()->GetMedianTimePast()-1;
+    CValidationState state4;
+    BOOST_CHECK(ProcessBlock(state4, NULL, pblock)==false);
+    BOOST_CHECK(!state4.IsValid());
+    BOOST_CHECK(state4.GetRejectReason()=="time-too-old");
+    // Do not update parent since block has failed
+
+    // Adding a non-final coinbase, must modify coinbase
+    CheckSubsidyHalving(pblocktemplate,pblock);
+    SetEmptyBlock(pblock);
+    // Use a mutable coinbase to change nLockTime and  nSequence
+    CMutableTransaction txCoinbase(pblock->vtx[0]);
+    txCoinbase.vin[0].scriptSig = (CScript() << chainActive.Height() << 0);
+    txCoinbase.nLockTime = LOCKTIME_THRESHOLD-1; // refers to height
+    txCoinbase.vin[0].nSequence = 1; // non-zero sequence
+    pblock->vtx[0] = CTransaction(txCoinbase);
+    pblock->nVersion = 2;
+    pblock->hashMerkleRoot = pblock->BuildMerkleTree();
+    CValidationState state5;
+    BOOST_CHECK(ProcessBlock(state5, NULL, pblock)==false);
+    BOOST_CHECK(!state5.IsValid());
+    BOOST_CHECK(state5.GetRejectReason()=="bad-txns-nonfinal");
+    // Do not update parent since block has failed
+
+
+    delete pblocktemplate;
+
+    ModifiableParams()->setSkipProofOfWorkCheck(false);
+    LogPrintf("Blockv2test testcase ends\n");
+}
+
+BOOST_AUTO_TEST_CASE(Blockv2testcase)
+{
+    Blockv2test();
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 9e4669eba..bad5c13ac 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -253,6 +253,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
 
     chainActive.Tip()->nHeight--;
     SetMockTime(0);
+    mempool.clear();
 
     BOOST_FOREACH(CTransaction *tx, txFirst)
         delete tx;
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
index 68fad8d03..6e5f0e3fa 100644
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -31,7 +31,7 @@ struct TestingSetup {
 
     TestingSetup() {
         fPrintToDebugLog = false; // don't want to write to debug.log file
-        SelectParams(CBaseChainParams::MAIN);
+        SelectParams(CBaseChainParams::UNITTEST);
         noui_connect();
 #ifdef ENABLE_WALLET
         bitdb.MakeMock();