diff --git a/eth/protocols/eth/protocol.go b/eth/protocols/eth/protocol.go
index d1e07df25c..46bc97fbb8 100644
--- a/eth/protocols/eth/protocol.go
+++ b/eth/protocols/eth/protocol.go
@@ -25,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/forkid"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
@@ -46,7 +47,7 @@ var ProtocolVersions = []uint{ETH68}
 var protocolLengths = map[uint]uint64{ETH68: 17}
 
 // maxMessageSize is the maximum cap on the size of a protocol message.
-const maxMessageSize = 10 * 1024 * 1024
+var maxMessageSize = params.MaxMessageSize
 
 const (
 	StatusMsg                     = 0x00
diff --git a/miner/bid_simulator.go b/miner/bid_simulator.go
index f96d3c1a8a..498f1ec2b2 100644
--- a/miner/bid_simulator.go
+++ b/miner/bid_simulator.go
@@ -692,6 +692,14 @@ func (b *bidSimulator) simBid(interruptCh chan int32, bidRuntime *BidRuntime) {
 		return
 	}
 
+	// check bid size
+	if bidRuntime.env.size+blockReserveSize > params.MaxMessageSize {
+		log.Error("BidSimulator: failed to check bid size", "builder", bidRuntime.bid.Builder,
+			"bidHash", bidRuntime.bid.Hash(), "env.size", bidRuntime.env.size)
+		err = errors.New("invalid bid size")
+		return
+	}
+
 	bestBid := b.GetBestBid(parentHash)
 	if bestBid == nil {
 		log.Info("[BID RESULT]", "win", "true[first]", "builder", bidRuntime.bid.Builder, "hash", bidRuntime.bid.Hash().TerminalString())
@@ -858,6 +866,7 @@ func (r *BidRuntime) commitTransaction(chain *core.BlockChain, chainConfig *para
 	}
 
 	r.env.tcount++
+	r.env.size += uint32(tx.Size())
 
 	return nil
 }
diff --git a/miner/worker.go b/miner/worker.go
index 8f09819d7d..8513b6a9b6 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -70,6 +70,12 @@ const (
 
 	// the default to wait for the mev miner to finish
 	waitMEVMinerEndTimeLimit = 50 * time.Millisecond
+
+	// Reserve block size for the following 3 components:
+	// a. System transactions at the end of the block
+	// b. Seal in the block header
+	// c. Overhead from RLP encoding
+	blockReserveSize = 100 * 1024
 )
 
 var (
@@ -89,6 +95,7 @@ type environment struct {
 	signer   types.Signer
 	state    *state.StateDB // apply state changes here
 	tcount   int            // tx count in cycle
+	size     uint32         // almost accurate block size,
 	gasPool  *core.GasPool  // available gas used to pack transactions
 	coinbase common.Address
 
@@ -105,6 +112,7 @@ func (env *environment) copy() *environment {
 		signer:   env.signer,
 		state:    env.state.Copy(),
 		tcount:   env.tcount,
+		size:     env.size,
 		coinbase: env.coinbase,
 		header:   types.CopyHeader(env.header),
 		receipts: copyReceipts(env.receipts),
@@ -895,6 +903,13 @@ LOOP:
 			txs.Pop()
 			continue
 		}
+		// If we don't have enough size left for the next transaction, skip it.
+		if env.size+uint32(tx.Size())+blockReserveSize > params.MaxMessageSize {
+			log.Trace("Not enough size left for transaction", "hash", ltx.Hash,
+				"env.size", env.size, "needed", uint32(tx.Size()))
+			txs.Pop()
+			continue
+		}
 		// Error may be ignored here. The error has already been checked
 		// during transaction acceptance is the transaction pool.
 		from, _ := types.Sender(env.signer, tx)
@@ -920,6 +935,7 @@ LOOP:
 			// Everything ok, collect the logs and shift in the next transaction from the same account
 			coalescedLogs = append(coalescedLogs, logs...)
 			env.tcount++
+			env.size += uint32(tx.Size()) // size of BlobTxSidecar included
 			txs.Shift()
 
 		default:
@@ -1055,6 +1071,9 @@ func (w *worker) prepareWork(genParams *generateParams) (*environment, error) {
 		vmenv := vm.NewEVM(context, vm.TxContext{}, env.state, w.chainConfig, vm.Config{})
 		core.ProcessBeaconBlockRoot(*header.ParentBeaconRoot, vmenv, env.state)
 	}
+
+	env.size = uint32(env.header.Size())
+
 	return env, nil
 }
 
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 65b2d942c1..a032f2759e 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -29,6 +29,8 @@ const (
 	GenesisGasLimit      uint64 = 4712388            // Gas limit of the Genesis block.
 	PayBidTxGasLimit     uint64 = 25000              // Gas limit of the PayBidTx in the types.BidArgs.
 
+	MaxMessageSize uint32 = 10 * 1024 * 1024 // MaxMessageSize is the maximum cap on the size of a eth protocol message.
+
 	MaximumExtraDataSize  uint64 = 32       // Maximum size extra data may be after Genesis.
 	ForkIDSize            uint64 = 4        // The length of fork id
 	ExpByteGas            uint64 = 10       // Times ceil(log256(exponent)) for the EXP instruction.