diff --git a/antelope_contracts/contracts/erc20/include/erc20/erc20.hpp b/antelope_contracts/contracts/erc20/include/erc20/erc20.hpp
index 830afaa..414ecba 100644
--- a/antelope_contracts/contracts/erc20/include/erc20/erc20.hpp
+++ b/antelope_contracts/contracts/erc20/include/erc20/erc20.hpp
@@ -56,7 +56,10 @@ class [[eosio::contract]] erc20 : public contract {
     [[eosio::action]] void withdrawfee(eosio::name token_contract, eosio::asset quantity, eosio::name to, std::string memo);
 
     [[eosio::action]] void unregtoken(eosio::name eos_contract_name, eosio::symbol_code token_symbol_code);
-    [[eosio::action]] void setconfig(std::optional<eosio::name> evm_account, std::optional<eosio::symbol> gas_token_symbol, std::optional<uint64_t> gaslimit, std::optional<uint64_t> init_gaslimit);
+
+    [[eosio::action]] void init(eosio::name evm_account, eosio::symbol gas_token_symbol, uint64_t gaslimit, uint64_t init_gaslimit);
+
+    [[eosio::action]] void setgaslimit(std::optional<uint64_t> gaslimit, std::optional<uint64_t> init_gaslimit);
     
     struct [[eosio::table("implcontract")]] impl_contract_t {
         uint64_t id = 0;
@@ -115,17 +118,17 @@ class [[eosio::contract]] erc20 : public contract {
         EOSLIB_SERIALIZE(config_t, (evm_gaslimit)(evm_init_gaslimit)(evm_account)(evm_gas_token_symbol));
     };
     typedef eosio::singleton<"config"_n, config_t> config_singleton_t;
+
     config_t get_config() const {
         config_singleton_t config(get_self(), get_self().value);
-        if (!config.exists()) {
-            return config_t{};
-        } else {
-            return config.get();
-        }
+        eosio::check(config.exists(), "erc20 config not exist");
+        return config.get();
     }
-    intx::uint256 get_minimum_natively_representable() const {
-        return intx::exp(10_u256, intx::uint256(evm_precision - get_config().evm_gas_token_symbol.precision()));
+
+    intx::uint256 get_minimum_natively_representable(const config_t& config) const {
+        return intx::exp(10_u256, intx::uint256(evm_precision - config.evm_gas_token_symbol.precision()));
     }
+    
     void set_config(const config_t &v) {
         config_singleton_t config(get_self(), get_self().value);
         config.set(v, get_self());
diff --git a/antelope_contracts/contracts/erc20/src/erc20.cpp b/antelope_contracts/contracts/erc20/src/erc20.cpp
index 875099d..1f77ad3 100644
--- a/antelope_contracts/contracts/erc20/src/erc20.cpp
+++ b/antelope_contracts/contracts/erc20/src/erc20.cpp
@@ -122,7 +122,7 @@ void erc20::upgradeto(std::string impl_address) {
 
     eosio::check(egress_fee.symbol == config.evm_gas_token_symbol, "egress_fee should have native token symbol");
     intx::uint256 egress_fee_evm = egress_fee.amount;
-    egress_fee_evm *= get_minimum_natively_representable();
+    egress_fee_evm *= get_minimum_natively_representable(config);
 
     token_table_t token_table(_self, _self.value);
     auto index_symbol = token_table.get_index<"by.symbol"_n>();
@@ -414,7 +414,7 @@ void erc20::setegressfee(eosio::name token_contract, eosio::symbol_code token_sy
     eosio::check(egress_fee >= message_receivers_iter->min_fee, "egress fee must be at least as large as the receiver's minimum fee");
     
     intx::uint256 egress_fee_evm = egress_fee.amount;
-    egress_fee_evm *= get_minimum_natively_representable();
+    egress_fee_evm *= get_minimum_natively_representable(config);
 
     auto pack_uint256 = [&](bytes &ds, const intx::uint256 &val) {
         uint8_t val_[32] = {};
@@ -446,12 +446,28 @@ void erc20::unregtoken(eosio::name token_contract, eosio::symbol_code token_symb
     index_symbol.erase(token_table_iter);
 }
 
-void erc20::setconfig(std::optional<eosio::name> evm_account, std::optional<eosio::symbol> gas_token_symbol, std::optional<uint64_t> gaslimit, std::optional<uint64_t> init_gaslimit) {
+void erc20::init(eosio::name evm_account, eosio::symbol gas_token_symbol, uint64_t gaslimit, uint64_t init_gaslimit) {
+    require_auth(get_self());
+
+    config_singleton_t config_table(get_self(), get_self().value);
+    eosio::check(!config_table.exists(), "erc20 config already initialized");
+
+    config_t config;
+    token_table_t token_table(_self, _self.value);
+    if (token_table.begin() != token_table.end()) {
+        eosio::check(evm_account == default_evm_account && gas_token_symbol == default_native_token_symbol, "can only init with native EOS symbol");
+    }
+    config.evm_account = evm_account;
+    config.evm_gas_token_symbol = gas_token_symbol;
+    config.evm_gaslimit = gaslimit;
+    config.evm_init_gaslimit = init_gaslimit;
+    set_config(config);
+}
+
+void erc20::setgaslimit(std::optional<uint64_t> gaslimit, std::optional<uint64_t> init_gaslimit) {
     require_auth(get_self());
 
     config_t config = get_config();
-    if (evm_account.has_value()) config.evm_account = *evm_account;
-    if (gas_token_symbol.has_value()) config.evm_gas_token_symbol = *gas_token_symbol;
     if (gaslimit.has_value()) config.evm_gaslimit = *gaslimit;
     if (init_gaslimit.has_value()) config.evm_init_gaslimit = *init_gaslimit;
     set_config(config);
diff --git a/antelope_contracts/tests/erc20/erc20_tester.cpp b/antelope_contracts/tests/erc20/erc20_tester.cpp
index 5e68c20..287c2f8 100644
--- a/antelope_contracts/tests/erc20/erc20_tester.cpp
+++ b/antelope_contracts/tests/erc20/erc20_tester.cpp
@@ -114,7 +114,7 @@ evm_eoa::~evm_eoa() { secp256k1_context_destroy(ctx); }
 
 
 
-erc20_tester::erc20_tester(bool use_real_evm, std::string native_symbol_str) : native_symbol(symbol::from_string(native_symbol_str)) {
+erc20_tester::erc20_tester(bool use_real_evm, eosio::chain::name evm_account_, std::string native_symbol_str) : evm_account(evm_account_), native_symbol(symbol::from_string(native_symbol_str)) {
     auto def_conf = default_config(tempdir, 4096);
 
     cfg = def_conf.first;
@@ -171,6 +171,15 @@ erc20_tester::erc20_tester(bool use_real_evm, std::string native_symbol_str) : n
     set_abi(erc20_account, testing::contracts::erc20_abi().data());
 
     produce_block();
+    
+    if (native_symbol_str.length()) {
+        push_action(erc20_account, "init"_n, erc20_account, mvo("evm_account", evm_account)("gas_token_symbol", native_symbol_str)("gaslimit", 500000)("init_gaslimit", 10000000));
+
+        BOOST_REQUIRE_EXCEPTION(
+            push_action(erc20_account, "init"_n, erc20_account, mvo("evm_account", evm_account)("gas_token_symbol", native_symbol_str)("gaslimit", 1)("init_gaslimit", 1)),
+            eosio_assert_message_exception, 
+            testing::eosio_assert_message_is("erc20 config already initialized"));
+    }
 
     if (use_real_evm) {
         set_code(evm_account, testing::contracts::evm_wasm());
@@ -316,6 +325,7 @@ transaction_trace_ptr erc20_tester::push_action(const account_name& code,
 
 transaction_trace_ptr erc20_tester::pushtx(const silkworm::Transaction& trx, name miner)
 {
+    if (miner == name()) miner = evm_account;
    silkworm::Bytes rlp;
    silkworm::rlp::encode(rlp, trx);
 
diff --git a/antelope_contracts/tests/erc20/erc20_tester.hpp b/antelope_contracts/tests/erc20/erc20_tester.hpp
index 5905ac6..18d07d3 100644
--- a/antelope_contracts/tests/erc20/erc20_tester.hpp
+++ b/antelope_contracts/tests/erc20/erc20_tester.hpp
@@ -113,7 +113,6 @@ constexpr uint64_t suggested_gas_price = 150'000'000'000;    // 150 gwei
 constexpr uint32_t suggested_miner_cut = 10'000;             // 10%
 constexpr uint64_t suggested_ingress_bridge_fee_amount = 70; // 0.0070 EOS
 
-extern const eosio::chain::name evm_account;
 extern const eosio::chain::name faucet_account_name;
 extern const eosio::chain::name erc20_account;
 extern const eosio::chain::name evmin_account;
@@ -126,14 +125,15 @@ class erc20_tester : public eosio::testing::base_tester {
    using testing::base_tester::push_action;
 
    static constexpr eosio::chain::name token_account = "tethertether"_n;
-   static constexpr eosio::chain::name evm_account = "eosio.evm"_n;
+    
    static constexpr eosio::chain::name faucet_account_name = "eosio.faucet"_n;
    static constexpr eosio::chain::name erc20_account = "eosio.erc2o"_n;
    static constexpr eosio::chain::name eos_system_account = "eosio"_n;
    static constexpr eosio::chain::name eos_token_account = "eosio.token"_n;
 
+    const eosio::chain::name evm_account = "eosio.evm"_n;
     const eosio::chain::symbol native_symbol;
-    explicit erc20_tester(bool use_real_evm = false, std::string native_symbol_str = "4,EOS");
+    explicit erc20_tester(bool use_real_evm = false, eosio::chain::name evm_account_ = "eosio.evm"_n, std::string native_symbol_str = "4,EOS");
 
     unsigned int exec_count = 0; // ensure uniqueness in exec
 
@@ -141,7 +141,7 @@ class erc20_tester : public eosio::testing::base_tester {
     eosio::chain::asset make_asset(int64_t amount, const eosio::chain::symbol& target_symbol) const { return eosio::chain::asset(amount, target_symbol); }
     eosio::chain::transaction_trace_ptr transfer_token(eosio::chain::name token_account_name, eosio::chain::name from, eosio::chain::name to, eosio::chain::asset quantity, std::string memo = "");
     void prepare_self_balance(uint64_t fund_amount = 100'0000);
-    transaction_trace_ptr bridgereg(eosio::chain::name receiver, eosio::chain::name handler, eosio::chain::asset min_fee, vector<account_name> extra_signers={evm_account});
+    transaction_trace_ptr bridgereg(eosio::chain::name receiver, eosio::chain::name handler, eosio::chain::asset min_fee, vector<account_name> extra_signers={"eosio.evm"_n});
     void open(name owner);
     transaction_trace_ptr exec(const exec_input& input, const std::optional<exec_callback>& callback);
     eosio::chain::action get_action( account_name code, action_name acttype, std::vector<permission_level> auths,
@@ -158,7 +158,7 @@ class erc20_tester : public eosio::testing::base_tester {
     generate_tx(const evmc::address& to, const intx::uint256& value, uint64_t gas_limit = 21000) const;
     silkworm::Transaction
     prepare_deploy_contract_tx(const unsigned char* contract, size_t size, uint64_t gas_limit) const;
-    transaction_trace_ptr pushtx(const silkworm::Transaction& trx, name miner = evm_account);
+    transaction_trace_ptr pushtx(const silkworm::Transaction& trx, name miner = {});
 
     eosio::chain::abi_serializer abi_ser;
     eosio::chain::abi_serializer token_abi_ser;
diff --git a/antelope_contracts/tests/erc20/integrated_tests.cpp b/antelope_contracts/tests/erc20/integrated_tests.cpp
index 5cafe01..515db5b 100644
--- a/antelope_contracts/tests/erc20/integrated_tests.cpp
+++ b/antelope_contracts/tests/erc20/integrated_tests.cpp
@@ -407,6 +407,19 @@ try {
     BOOST_REQUIRE(tokenInfo.fee_balance == make_asset(200, token_symbol));
     produce_block();
 
+    // setting a lower gas limit, USDT(EOS)-> USDT(EVM) will fails
+    push_action(erc20_account, "setgaslimit"_n, erc20_account, mvo("gaslimit", 21001)("init_gaslimit", 10000000));
+
+    BOOST_REQUIRE_EXCEPTION(
+        transfer_token(token_account, "alice"_n, erc20_account, make_asset(102, token_symbol), evm1.address_0x().c_str()),
+        eosio_assert_message_exception, 
+        eosio_assert_message_is("pre_validate_transaction error: 22 Intrinsic gas too low")
+    );
+
+    // set it back
+    push_action(erc20_account, "setgaslimit"_n, erc20_account, mvo("gaslimit", 500000)("init_gaslimit", 10000000));
+    transfer_token(token_account, "alice"_n, erc20_account, make_asset(103, token_symbol), evm1.address_0x().c_str());
+
 }
 FC_LOG_AND_RETHROW()