diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 52ccc44cf5..48f4e3c309 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -74,7 +74,7 @@ jobs:
       - name: test & coverage report creation
         if: env.GIT_DIFF
         run: |
-          cat pkgs.txt.part.${{ matrix.part }} | xargs go test -mod=readonly -race -timeout 30m -coverprofile=${{ matrix.part }}profile.out -covermode=atomic -tags='ledger test_ledger_mock'
+          cat pkgs.txt.part.${{ matrix.part }} | xargs go test -mod=readonly -race -timeout 60m -coverprofile=${{ matrix.part }}profile.out -covermode=atomic -tags='ledger test_ledger_mock'
       - uses: actions/upload-artifact@v3
         if: env.GIT_DIFF
         with:
@@ -256,9 +256,9 @@ jobs:
         if: env.GIT_DIFF
         run: |
           cd simapp
-          go test -mod=readonly -timeout 30m -coverprofile=coverage.out -covermode=atomic -tags='norace ledger test_ledger_mock rocksdb_build' ./...
+          go test -mod=readonly -timeout 60m -coverprofile=coverage.out -covermode=atomic -tags='norace ledger test_ledger_mock rocksdb_build' ./...
       - name: tests simapp v1
         if: env.GIT_DIFF
         run: |
           cd simapp
-          go test -mod=readonly -timeout 30m -tags='app_v1 norace ledger test_ledger_mock rocksdb_build' ./...
\ No newline at end of file
+          go test -mod=readonly -timeout 60m -tags='app_v1 norace ledger test_ledger_mock rocksdb_build' ./...
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7e8ce92389..00e214a23e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,11 @@
 # Changelog
+
+## v0.2.1
+This release is a hot fix release for v0.2.0.
+
+* [\#203](https://github.com/bnb-chain/greenfield-cosmos-sdk/pull/203) fix: update DefaultMaxTxSize and gas simulation logic
+* [\#204](https://github.com/bnb-chain/greenfield-cosmos-sdk/pull/204) fix: allow GasParams fixedtype's gas is zero
+
 ## v0.2.0
 This release upgrades the reference cosmos-sdk to v0.47.2. As the cosmos-sdk v0.47.2 is a huge breaking upgrade, 
 we decide to cherry-pick the recent contributed commits and apply to the v0.47.2. The commit history previous 
diff --git a/x/gashub/types/gas_calculator.go b/x/gashub/types/gas_calculator.go
index 382ba424f2..f01e1fbc23 100644
--- a/x/gashub/types/gas_calculator.go
+++ b/x/gashub/types/gas_calculator.go
@@ -63,9 +63,6 @@ func GetGasCalculatorGen(mgp MsgGasParams) (GasCalculatorGenerator, error) {
 
 func FixedGasCalculator(amount uint64) GasCalculator {
 	return func(msg types.Msg) (uint64, error) {
-		if amount == 0 {
-			return 0, errorsmod.Wrapf(errors.ErrInvalidMsgGasParams, "msg type: %s", types.MsgTypeURL(msg))
-		}
 		return amount, nil
 	}
 }
diff --git a/x/gashub/types/genesis.go b/x/gashub/types/genesis.go
index cbd3451820..c7dd044764 100644
--- a/x/gashub/types/genesis.go
+++ b/x/gashub/types/genesis.go
@@ -40,6 +40,24 @@ func NewGenesisState(params Params, msgGasParamsSet []MsgGasParams) *GenesisStat
 // DefaultGenesisState - Return a default genesis state
 func DefaultGenesisState() *GenesisState {
 	defaultMsgGasParamsSet := []MsgGasParams{
+		*NewMsgGasParamsWithFixedGas("/cosmos.auth.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.bank.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.consensus.v1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.crisis.v1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.crosschain.v1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.distribution.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.gashub.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.gov.v1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.mint.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.oracle.v1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.slashing.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/cosmos.staking.v1beta1.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.bridge.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.sp.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.storage.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.payment.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.challenge.MsgUpdateParams", 0),
+		*NewMsgGasParamsWithFixedGas("/greenfield.permission.MsgUpdateParams", 0),
 		*NewMsgGasParamsWithFixedGas("/cosmos.authz.v1beta1.MsgExec", 1.2e3),
 		*NewMsgGasParamsWithFixedGas("/cosmos.authz.v1beta1.MsgRevoke", 1.2e3),
 		*NewMsgGasParamsWithFixedGas("/cosmos.bank.v1beta1.MsgSend", 1.2e3),
diff --git a/x/gashub/types/params.go b/x/gashub/types/params.go
index 8130ac0c3b..39c6931fb4 100644
--- a/x/gashub/types/params.go
+++ b/x/gashub/types/params.go
@@ -92,9 +92,7 @@ func (mgp MsgGasParams) Validate() error {
 
 	switch p := mgp.GasParams.(type) {
 	case *MsgGasParams_FixedType:
-		if p.FixedType.FixedGas == 0 {
-			return fmt.Errorf("invalid gas. cannot be zero")
-		}
+		return nil
 	case *MsgGasParams_GrantType:
 		if p.GrantType.FixedGas == 0 || p.GrantType.GasPerItem == 0 {
 			return fmt.Errorf("invalid gas. cannot be zero")