diff --git a/execution/gethexec/api.go b/execution/gethexec/api.go
index 713d1496f9..699aa081b5 100644
--- a/execution/gethexec/api.go
+++ b/execution/gethexec/api.go
@@ -17,6 +17,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
 
 	"github.com/offchainlabs/nitro/arbos/arbosState"
@@ -285,14 +286,16 @@ func stateAndHeader(blockchain *core.BlockChain, block uint64) (*arbosState.Arbo
 type ArbTraceForwarderAPI struct {
 	fallbackClientUrl     string
 	fallbackClientTimeout time.Duration
+	blockchainConfig      *params.ChainConfig
 
 	initialized    atomic.Bool
 	mutex          sync.Mutex
 	fallbackClient types.FallbackClient
 }
 
-func NewArbTraceForwarderAPI(fallbackClientUrl string, fallbackClientTimeout time.Duration) *ArbTraceForwarderAPI {
+func NewArbTraceForwarderAPI(blockchainConfig *params.ChainConfig, fallbackClientUrl string, fallbackClientTimeout time.Duration) *ArbTraceForwarderAPI {
 	return &ArbTraceForwarderAPI{
+		blockchainConfig:      blockchainConfig,
 		fallbackClientUrl:     fallbackClientUrl,
 		fallbackClientTimeout: fallbackClientTimeout,
 	}
@@ -332,16 +335,45 @@ func (api *ArbTraceForwarderAPI) forward(ctx context.Context, method string, arg
 	return resp, nil
 }
 
-func (api *ArbTraceForwarderAPI) Call(ctx context.Context, callArgs json.RawMessage, traceTypes json.RawMessage, blockNum json.RawMessage) (*json.RawMessage, error) {
-	return api.forward(ctx, "arbtrace_call", callArgs, traceTypes, blockNum)
+func (api *ArbTraceForwarderAPI) blockSupportedByClassicNode(blockNumOrHash json.RawMessage) error {
+	var bnh rpc.BlockNumberOrHash
+	err := bnh.UnmarshalJSON(blockNumOrHash)
+	if err != nil {
+		return err
+	}
+	blockNum, isNum := bnh.Number()
+	if !isNum {
+		return nil
+	}
+	// #nosec G115
+	if blockNum < 0 || blockNum > rpc.BlockNumber(api.blockchainConfig.ArbitrumChainParams.GenesisBlockNum) {
+		return fmt.Errorf("block number %v is not supported by classic node", blockNum)
+	}
+	return nil
 }
 
-func (api *ArbTraceForwarderAPI) CallMany(ctx context.Context, calls json.RawMessage, blockNum json.RawMessage) (*json.RawMessage, error) {
-	return api.forward(ctx, "arbtrace_callMany", calls, blockNum)
+func (api *ArbTraceForwarderAPI) Call(ctx context.Context, callArgs json.RawMessage, traceTypes json.RawMessage, blockNumOrHash json.RawMessage) (*json.RawMessage, error) {
+	err := api.blockSupportedByClassicNode(blockNumOrHash)
+	if err != nil {
+		return nil, err
+	}
+	return api.forward(ctx, "arbtrace_call", callArgs, traceTypes, blockNumOrHash)
 }
 
-func (api *ArbTraceForwarderAPI) ReplayBlockTransactions(ctx context.Context, blockNum json.RawMessage, traceTypes json.RawMessage) (*json.RawMessage, error) {
-	return api.forward(ctx, "arbtrace_replayBlockTransactions", blockNum, traceTypes)
+func (api *ArbTraceForwarderAPI) CallMany(ctx context.Context, calls json.RawMessage, blockNumOrHash json.RawMessage) (*json.RawMessage, error) {
+	err := api.blockSupportedByClassicNode(blockNumOrHash)
+	if err != nil {
+		return nil, err
+	}
+	return api.forward(ctx, "arbtrace_callMany", calls, blockNumOrHash)
+}
+
+func (api *ArbTraceForwarderAPI) ReplayBlockTransactions(ctx context.Context, blockNumOrHash json.RawMessage, traceTypes json.RawMessage) (*json.RawMessage, error) {
+	err := api.blockSupportedByClassicNode(blockNumOrHash)
+	if err != nil {
+		return nil, err
+	}
+	return api.forward(ctx, "arbtrace_replayBlockTransactions", blockNumOrHash, traceTypes)
 }
 
 func (api *ArbTraceForwarderAPI) ReplayTransaction(ctx context.Context, txHash json.RawMessage, traceTypes json.RawMessage) (*json.RawMessage, error) {
@@ -356,8 +388,12 @@ func (api *ArbTraceForwarderAPI) Get(ctx context.Context, txHash json.RawMessage
 	return api.forward(ctx, "arbtrace_get", txHash, path)
 }
 
-func (api *ArbTraceForwarderAPI) Block(ctx context.Context, blockNum json.RawMessage) (*json.RawMessage, error) {
-	return api.forward(ctx, "arbtrace_block", blockNum)
+func (api *ArbTraceForwarderAPI) Block(ctx context.Context, blockNumOrHash json.RawMessage) (*json.RawMessage, error) {
+	err := api.blockSupportedByClassicNode(blockNumOrHash)
+	if err != nil {
+		return nil, err
+	}
+	return api.forward(ctx, "arbtrace_block", blockNumOrHash)
 }
 
 func (api *ArbTraceForwarderAPI) Filter(ctx context.Context, filter json.RawMessage) (*json.RawMessage, error) {
diff --git a/execution/gethexec/node.go b/execution/gethexec/node.go
index 11d173a21e..16e4948723 100644
--- a/execution/gethexec/node.go
+++ b/execution/gethexec/node.go
@@ -284,6 +284,7 @@ func CreateExecutionNode(
 		Namespace: "arbtrace",
 		Version:   "1.0",
 		Service: NewArbTraceForwarderAPI(
+			l2BlockChain.Config(),
 			config.RPC.ClassicRedirect,
 			config.RPC.ClassicRedirectTimeout,
 		),