diff --git a/src/miner.h b/src/miner.h
--- a/src/miner.h
+++ b/src/miner.h
@@ -213,10 +213,10 @@
 };
 
 /** Modify the extranonce in a block */
-void IncrementExtraNonce(CBlock *pblock, const CBlockIndex *pindexPrev,
+void IncrementExtraNonce(const Config &config, CBlock *pblock,
+                         const CBlockIndex *pindexPrev,
                          unsigned int &nExtraNonce);
 int64_t UpdateTime(CBlockHeader *pblock,
                    const Consensus::Params &consensusParams,
                    const CBlockIndex *pindexPrev);
-
 #endif // BITCOIN_MINER_H
diff --git a/src/miner.cpp b/src/miner.cpp
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -33,6 +33,8 @@
 #include <boost/thread.hpp>
 #include <boost/tuple/tuple.hpp>
 
+static const int MAX_COINBASE_SCRIPTSIG_SIZE = 100;
+
 //////////////////////////////////////////////////////////////////////////////
 //
 // BitcoinMiner
@@ -142,6 +144,14 @@
     blockFinished = false;
 }
 
+static const std::vector<unsigned char>
+getExcessiveBlockSizeSig(const Config &config) {
+    std::string cbmsg = "/EB" + getSubVersionEB(config.GetMaxBlockSize()) + "/";
+    const char *cbcstr = cbmsg.c_str();
+    std::vector<unsigned char> vec(cbcstr, cbcstr + cbmsg.size());
+    return vec;
+}
+
 std::unique_ptr<CBlockTemplate>
 BlockAssembler::CreateNewBlock(const CScript &scriptPubKeyIn) {
     int64_t nTimeStart = GetTimeMicros();
@@ -199,7 +209,7 @@
     coinbaseTx.vout[0].nValue =
         nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus());
     coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0;
-    pblock->vtx[0] = MakeTransactionRef(coinbaseTx);
+    pblock->vtx[0] = MakeTransactionRef(std::move(coinbaseTx));
     pblocktemplate->vTxFees[0] = -nFees;
 
     uint64_t nSerializeSize =
@@ -658,7 +668,8 @@
     }
 }
 
-void IncrementExtraNonce(CBlock *pblock, const CBlockIndex *pindexPrev,
+void IncrementExtraNonce(const Config &config, CBlock *pblock,
+                         const CBlockIndex *pindexPrev,
                          unsigned int &nExtraNonce) {
     // Update nExtraNonce
     static uint256 hashPrevBlock;
@@ -671,8 +682,10 @@
     unsigned int nHeight = pindexPrev->nHeight + 1;
     CMutableTransaction txCoinbase(*pblock->vtx[0]);
     txCoinbase.vin[0].scriptSig =
-        (CScript() << nHeight << CScriptNum(nExtraNonce)) + COINBASE_FLAGS;
-    assert(txCoinbase.vin[0].scriptSig.size() <= 100);
+        (CScript() << nHeight << CScriptNum(nExtraNonce)
+                   << getExcessiveBlockSizeSig(config)) +
+        COINBASE_FLAGS;
+    assert(txCoinbase.vin[0].scriptSig.size() <= MAX_COINBASE_SCRIPTSIG_SIZE);
 
     pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
     pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -130,7 +130,7 @@
         CBlock *pblock = &pblocktemplate->block;
         {
             LOCK(cs_main);
-            IncrementExtraNonce(pblock, chainActive.Tip(), nExtraNonce);
+            IncrementExtraNonce(config, pblock, chainActive.Tip(), nExtraNonce);
         }
         while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount &&
                !CheckProofOfWork(pblock->GetHash(), pblock->nBits,
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -202,6 +202,42 @@
     BOOST_CHECK(pblocktemplate->block.vtx[8]->GetId() == hashLowFeeTx2);
 }
 
+void TestCoinbaseMessageEB(uint64_t eb, std::string cbmsg) {
+
+    GlobalConfig config;
+    config.SetMaxBlockSize(eb);
+    const CChainParams &chainparams = config.GetChainParams();
+
+    CScript scriptPubKey =
+        CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909"
+                              "a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112"
+                              "de5c384df7ba0b8d578a4c702b6bf11d5f")
+                  << OP_CHECKSIG;
+
+    std::unique_ptr<CBlockTemplate> pblocktemplate =
+        BlockAssembler(config, chainparams).CreateNewBlock(scriptPubKey);
+
+    CBlock *pblock = &pblocktemplate->block;
+
+    // IncrementExtraNonce creates a valid coinbase and merkleRoot
+    unsigned int extraNonce = 0;
+    IncrementExtraNonce(config, pblock, chainActive.Tip(), extraNonce);
+    unsigned int nHeight = chainActive.Tip()->nHeight + 1;
+    std::vector<unsigned char> vec(cbmsg.begin(), cbmsg.end());
+    BOOST_CHECK(pblock->vtx[0]->vin[0].scriptSig ==
+                ((CScript() << nHeight << CScriptNum(extraNonce) << vec) +
+                 COINBASE_FLAGS));
+}
+
+// Coinbase scriptSig has to contains the correct EB value
+// converted to MB, rounded down to the first decimal
+BOOST_AUTO_TEST_CASE(CheckCoinbase_EB) {
+    TestCoinbaseMessageEB(1000001, "/EB1.0/");
+    TestCoinbaseMessageEB(2000000, "/EB2.0/");
+    TestCoinbaseMessageEB(8000000, "/EB8.0/");
+    TestCoinbaseMessageEB(8320000, "/EB8.3/");
+}
+
 // NOTE: These tests rely on CreateNewBlock doing its own self-validation!
 BOOST_AUTO_TEST_CASE(CreateNewBlock_validity) {
     // Note that by default, these tests run with size accounting enabled.
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -117,8 +117,9 @@
 CBlock TestChain100Setup::CreateAndProcessBlock(
     const std::vector<CMutableTransaction> &txns, const CScript &scriptPubKey) {
     const CChainParams &chainparams = Params();
+    const Config &config = GetConfig();
     std::unique_ptr<CBlockTemplate> pblocktemplate =
-        BlockAssembler(GetConfig(), chainparams).CreateNewBlock(scriptPubKey);
+        BlockAssembler(config, chainparams).CreateNewBlock(scriptPubKey);
     CBlock &block = pblocktemplate->block;
 
     // Replace mempool-selected txns with just coinbase plus passed-in txns:
@@ -128,7 +129,7 @@
     }
     // IncrementExtraNonce creates a valid coinbase and merkleRoot
     unsigned int extraNonce = 0;
-    IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    IncrementExtraNonce(config, &block, chainActive.Tip(), extraNonce);
 
     while (!CheckProofOfWork(block.GetHash(), block.nBits,
                              chainparams.GetConsensus()))