diff --git a/rpc/packages.go b/rpc/packages.go
index 97227a64d..0f00441d2 100644
--- a/rpc/packages.go
+++ b/rpc/packages.go
@@ -25,9 +25,9 @@ import (
 	"github.com/ethereum/go-ethereum/xeth"
 )
 
-const (
-	defaultGasPrice = "10000000000000"
-	defaultGas      = "10000"
+var (
+	defaultGasPrice = big.NewInt(10000000000000)
+	defaultGas      = big.NewInt(10000)
 )
 
 type EthereumApi struct {
@@ -185,11 +185,11 @@ func (p *EthereumApi) GetBlock(args *GetBlockArgs, reply *interface{}) error {
 
 func (p *EthereumApi) Transact(args *NewTxArgs, reply *interface{}) error {
 	if len(args.Gas) == 0 {
-		args.Gas = defaultGas
+		args.Gas = defaultGas.String()
 	}
 
 	if len(args.GasPrice) == 0 {
-		args.GasPrice = defaultGasPrice
+		args.GasPrice = defaultGasPrice.String()
 	}
 
 	// TODO if no_private_key then
@@ -516,7 +516,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		}
 		return p.AllLogs(args, reply)
 	case "eth_gasPrice":
-		*reply = defaultGasPrice
+		*reply = toHex(defaultGasPrice.Bytes())
 		return nil
 	case "eth_register":
 		args, err := req.ToRegisterArgs()