diff --git a/eth/ethconfig/config.go b/eth/ethconfig/config.go
index 37b36ee4f5..c325e5010c 100644
--- a/eth/ethconfig/config.go
+++ b/eth/ethconfig/config.go
@@ -18,6 +18,7 @@
 package ethconfig
 
 import (
+	"fmt"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -161,6 +162,9 @@ type Config struct {
 // Clique is allowed for now to live standalone, but ethash is forbidden and can
 // only exist on already merged networks.
 func CreateConsensusEngine(config *params.ChainConfig, db ethdb.Database) (consensus.Engine, error) {
+	if config.TerminalTotalDifficulty == nil {
+		return nil, fmt.Errorf("only PoS networks are supported, please transition old ones with Geth v1.13.x")
+	}
 	// Wrap previously supported consensus engines into their post-merge counterpart
 	if config.Clique != nil {
 		return beacon.New(clique.New(config.Clique, db)), nil
diff --git a/params/config.go b/params/config.go
index 90191194c3..280972b45f 100644
--- a/params/config.go
+++ b/params/config.go
@@ -360,17 +360,9 @@ func (c *ChainConfig) Description() string {
 	banner += fmt.Sprintf("Chain ID:  %v (%s)\n", c.ChainID, network)
 	switch {
 	case c.Ethash != nil:
-		if c.TerminalTotalDifficulty == nil {
-			banner += "Consensus: Ethash (proof-of-work)\n"
-		} else {
-			banner += "Consensus: Beacon (proof-of-stake), merged from Ethash (proof-of-work)\n"
-		}
+		banner += "Consensus: Beacon (proof-of-stake), merged from Ethash (proof-of-work)\n"
 	case c.Clique != nil:
-		if c.TerminalTotalDifficulty == nil {
-			banner += "Consensus: Clique (proof-of-authority)\n"
-		} else {
-			banner += "Consensus: Beacon (proof-of-stake), merged from Clique (proof-of-authority)\n"
-		}
+		banner += "Consensus: Beacon (proof-of-stake), merged from Clique (proof-of-authority)\n"
 	default:
 		banner += "Consensus: unknown\n"
 	}
@@ -405,17 +397,12 @@ func (c *ChainConfig) Description() string {
 	banner += "\n"
 
 	// Add a special section for the merge as it's non-obvious
-	if c.TerminalTotalDifficulty == nil {
-		banner += "The Merge is not yet available for this network!\n"
-		banner += " - Hard-fork specification: https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/paris.md\n"
-	} else {
-		banner += "Merge configured:\n"
-		banner += " - Hard-fork specification:    https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/paris.md\n"
-		banner += " - Network known to be merged\n"
-		banner += fmt.Sprintf(" - Total terminal difficulty:  %v\n", c.TerminalTotalDifficulty)
-		if c.MergeNetsplitBlock != nil {
-			banner += fmt.Sprintf(" - Merge netsplit block:       #%-8v\n", c.MergeNetsplitBlock)
-		}
+	banner += "Merge configured:\n"
+	banner += " - Hard-fork specification:    https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/paris.md\n"
+	banner += " - Network known to be merged\n"
+	banner += fmt.Sprintf(" - Total terminal difficulty:  %v\n", c.TerminalTotalDifficulty)
+	if c.MergeNetsplitBlock != nil {
+		banner += fmt.Sprintf(" - Merge netsplit block:       #%-8v\n", c.MergeNetsplitBlock)
 	}
 	banner += "\n"