diff --git a/contract/contract.go b/contract/contract.go
index df67dba3..a2e2cdc3 100644
--- a/contract/contract.go
+++ b/contract/contract.go
@@ -20,11 +20,7 @@ const (
 	CrosschainAddress = "0x0000000000000000000000000000000000001004"
 )
 
-const (
-	DefaultGasCap uint64 = 30000000
-)
-
-var typeString, _ = abi.NewType("string", "", nil)
+const DefaultGasCap uint64 = 30000000
 
 var (
 	fip20Init = Contract{
@@ -95,11 +91,6 @@ func MustABIJson(str string) abi.ABI {
 	return j
 }
 
-func PackRetError(err error) ([]byte, error) {
-	pack, _ := abi.Arguments{{Type: typeString}}.Pack(err.Error())
-	return pack, err
-}
-
 func PackRetErrV2(err error) ([]byte, error) {
 	pack, _ := errorABI.Pack("Error", err.Error())
 	return pack, err
diff --git a/x/staking/precompile/contract.go b/x/staking/precompile/contract.go
index be17e707..5903ed45 100644
--- a/x/staking/precompile/contract.go
+++ b/x/staking/precompile/contract.go
@@ -99,7 +99,7 @@ func (c *Contract) Run(evm *vm.EVM, vmContract *vm.Contract, readonly bool) (ret
 
 			stateDB := evm.StateDB.(evmtypes.ExtStateDB)
 			if err = c.govKeeper.CheckDisabledPrecompiles(stateDB.Context(), c.Address(), vmContract.Input[:4]); err != nil {
-				return contract.PackRetError(err)
+				return contract.PackRetErrV2(err)
 			}
 
 			ret, err = method.Run(evm, vmContract)