diff --git a/src/miner.cpp b/src/miner.cpp
index 25eb7eec4..d36ade59c 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -176,6 +176,8 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
     pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
     pblock->nNonce         = nHeight; // nNonce now holds the height for Cryptonight variant 4
+    pblock->cnHeader.major_version  = Params().GetConsensus().GetCryptonoteMajorVersion();
+    pblock->cnHeader.prev_id        = pblock->GetOriginalBlockHash();
     pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]);
 
     CValidationState state;
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
index 3ef5ce928..860220973 100644
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -42,7 +42,8 @@ def create_block(hashprev, coinbase, nTime=None):
     assert block.nNonce > 0
     block.major_version = 10 # CN variant 4
     block.timestamp = block.nTime
-
+    # Give merkle root a random value.
+    block.merkle_root = uint256_from_str(bytes.fromhex("3cf6c3b6da3f4058853ee70369ee43d473aca91ae8fc8f44a645beb21c392d80"))
     block.calc_sha256()
     return block
 
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index a072682ee..faec0beb6 100644
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -630,9 +630,6 @@ class CBlockHeader():
 
             c += ser_uint256(self.prev_id)
             c += struct.pack("<I", self.nonce)
-
-            # hardcoded merkle root.
-            self.merkle_root = uint256_from_str(bytes.fromhex("3cf6c3b6da3f4058853ee70369ee43d473aca91ae8fc8f44a645beb21c392d80"))
             c += ser_uint256(self.merkle_root)
             c += struct.pack("<B", self.nTxes)
             # self.sha256 stores the cn_fast hash.