diff --git a/ethclient/ethclient.go b/ethclient/ethclient.go
index fbffe2678f..93d63d4ef3 100644
--- a/ethclient/ethclient.go
+++ b/ethclient/ethclient.go
@@ -18,7 +18,6 @@
 package ethclient
 
 import (
-	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -698,40 +697,36 @@ func (ec *Client) SendTransaction(ctx context.Context, tx *types.Transaction) er
 	return ec.c.CallContext(ctx, nil, "eth_sendRawTransaction", hexutil.Encode(data))
 }
 
-// SendRawTransactionSync submits a signed tx and waits for a receipt (or until
+// SendTransactionSync submits a signed tx and waits for a receipt (or until
 // the optional timeout elapses on the server side). If timeout == 0, the server
 // uses its default.
-func (ec *Client) SendRawTransactionSync(
+func (ec *Client) SendTransactionSync(
 	ctx context.Context,
 	tx *types.Transaction,
-	timeout time.Duration,
+	timeout ...time.Duration,
 ) (*types.Receipt, error) {
-	var buf bytes.Buffer
-	if err := tx.EncodeRLP(&buf); err != nil {
+	raw, err := tx.MarshalBinary()
+	if err != nil {
 		return nil, err
 	}
-	return ec.SendRawTransactionSyncRaw(ctx, buf.Bytes(), timeout)
+	return ec.SendRawTransactionSync(ctx, raw, timeout...)
 }
 
-// SendRawTransactionSyncRaw is the low-level variant that takes the raw RLP.
-func (ec *Client) SendRawTransactionSyncRaw(
+func (ec *Client) SendRawTransactionSync(
 	ctx context.Context,
 	rawTx []byte,
-	timeout time.Duration,
+	timeout ...time.Duration,
 ) (*types.Receipt, error) {
-	var out *types.Receipt
-
-	// Build params: raw bytes as hex, plus optional timeout as hexutil.Uint64
-	params := []any{hexutil.Bytes(rawTx)}
-	if timeout > 0 {
-		t := hexutil.Uint64(timeout.Milliseconds())
-		params = append(params, t)
+	var ms *hexutil.Uint64
+	if len(timeout) > 0 && timeout[0] > 0 {
+		v := hexutil.Uint64(timeout[0] / time.Millisecond)
+		ms = &v
 	}
-
-	if err := ec.c.CallContext(ctx, &out, "eth_sendRawTransactionSync", params...); err != nil {
+	var receipt types.Receipt
+	if err := ec.c.CallContext(ctx, &receipt, "eth_sendRawTransactionSync", hexutil.Bytes(rawTx), ms); err != nil {
 		return nil, err
 	}
-	return out, nil
+	return &receipt, nil
 }
 
 // RevertErrorData returns the 'revert reason' data of a contract call.