diff --git a/cmd/geth/genesis_test.go b/cmd/geth/genesis_test.go
index 7adc9d2658..2766be2deb 100644
--- a/cmd/geth/genesis_test.go
+++ b/cmd/geth/genesis_test.go
@@ -29,7 +29,7 @@ var customGenesisTests = []struct {
 	query   string
 	result  string
 }{
-	// Genesis file with an empty chain configuration (ensure missing fields work)
+	// Genesis file with a mostly-empty chain configuration (ensure missing fields work)
 	{
 		genesis: `{
 			"alloc"      : {},
@@ -41,7 +41,9 @@ var customGenesisTests = []struct {
 			"mixhash"    : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"timestamp"  : "0x00",
-			"config": {}
+			"config": {
+				"terminalTotalDifficulty": "0xffffffffffffffff"
+			}
 		}`,
 		query:  "eth.getBlock(0).nonce",
 		result: "0x0000000000001338",
@@ -61,7 +63,8 @@ var customGenesisTests = []struct {
 			"config"     : {
 				"homesteadBlock"                : 42,
 				"daoForkBlock"                  : 141,
-				"daoForkSupport"                : true
+				"daoForkSupport"                : true,
+				"terminalTotalDifficulty": "0xffffffffffffffff"
 			}
 		}`,
 		query:  "eth.getBlock(0).nonce",
@@ -111,7 +114,9 @@ func TestCustomBackend(t *testing.T) {
 			"mixhash"    : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
 			"timestamp"  : "0x00",
-			"config": {}
+			"config": {
+				"terminalTotalDifficulty": "0xffffffffffffffff"
+			}
 		}`
 	type backendTest struct {
 		initArgs   []string
diff --git a/cmd/geth/testdata/clique.json b/cmd/geth/testdata/clique.json
index b54b4a7d3b..d318f4c166 100644
--- a/cmd/geth/testdata/clique.json
+++ b/cmd/geth/testdata/clique.json
@@ -8,6 +8,7 @@
     "byzantiumBlock": 0,
     "constantinopleBlock": 0,
     "petersburgBlock": 0,
+    "terminalTotalDifficulty": 0,
     "clique": {
       "period": 5,
       "epoch": 30000
@@ -21,4 +22,4 @@
       "balance": "300000"
     }
   }
-}
\ No newline at end of file
+}
diff --git a/consensus/beacon/consensus.go b/consensus/beacon/consensus.go
index ae4c9f29a1..cbeb5e88d6 100644
--- a/consensus/beacon/consensus.go
+++ b/consensus/beacon/consensus.go
@@ -19,8 +19,6 @@ package beacon
 import (
 	"errors"
 	"fmt"
-	"math/big"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip1559"
@@ -32,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/ethereum/go-ethereum/trie"
 	"github.com/holiman/uint256"
+	"math/big"
 )
 
 // Proof-of-stake protocol constants.
@@ -115,9 +114,6 @@ func errOut(n int, err error) chan error {
 func (beacon *Beacon) splitHeaders(chain consensus.ChainHeaderReader, headers []*types.Header) ([]*types.Header, []*types.Header, error) {
 	// TTD is not defined yet, all headers should be in legacy format.
 	ttd := chain.Config().TerminalTotalDifficulty
-	if ttd == nil {
-		return headers, nil, nil
-	}
 	ptd := chain.GetTd(headers[0].ParentHash, headers[0].Number.Uint64()-1)
 	if ptd == nil {
 		return nil, nil, consensus.ErrUnknownAncestor
@@ -494,9 +490,6 @@ func (beacon *Beacon) SetThreads(threads int) {
 // It depends on the parentHash already being stored in the database.
 // If the parentHash is not stored in the database a UnknownAncestor error is returned.
 func IsTTDReached(chain consensus.ChainHeaderReader, parentHash common.Hash, parentNumber uint64) (bool, error) {
-	if chain.Config().TerminalTotalDifficulty == nil {
-		return false, nil
-	}
 	td := chain.GetTd(parentHash, parentNumber)
 	if td == nil {
 		return false, consensus.ErrUnknownAncestor
diff --git a/core/block_validator_test.go b/core/block_validator_test.go
index 80e6820661..03e2079b10 100644
--- a/core/block_validator_test.go
+++ b/core/block_validator_test.go
@@ -115,6 +115,8 @@ func testHeaderVerificationForMerging(t *testing.T, isClique bool) {
 
 		td := 0
 		genDb, blocks, _ := GenerateChainWithGenesis(gspec, engine, 8, nil)
+		gspec.Config.TerminalTotalDifficulty = big.NewInt(1000)
+
 		for i, block := range blocks {
 			header := block.Header()
 			if i > 0 {