diff --git a/app/ante/handler_options.go b/app/ante/handler_options.go
index 2a3cf544..5a1b6039 100644
--- a/app/ante/handler_options.go
+++ b/app/ante/handler_options.go
@@ -31,19 +31,19 @@ type HandlerOptions struct {
 }
 
 func (options HandlerOptions) validate() error {
-	if options.AccountKeeper == nil {
+	if options.AccountKeeper == evmtypes.AccountKeeper(nil) {
 		return sdkerrors.Wrap(sdkerrors.ErrLogic, "account keeper is required for AnteHandler")
 	}
-	if options.BankKeeper == nil {
+	if options.BankKeeper == evmtypes.BankKeeper(nil) {
 		return sdkerrors.Wrap(sdkerrors.ErrLogic, "bank keeper is required for AnteHandler")
 	}
-	if options.SignModeHandler == nil {
+	if options.SignModeHandler == authsigning.SignModeHandler(nil) {
 		return sdkerrors.Wrap(sdkerrors.ErrLogic, "sign mode handler is required for ante builder")
 	}
-	if options.FeeMarketKeeper == nil {
+	if options.FeeMarketKeeper == evmtypes.FeeMarketKeeper(nil) {
 		return sdkerrors.Wrap(sdkerrors.ErrLogic, "fee market keeper is required for AnteHandler")
 	}
-	if options.EvmKeeper == nil {
+	if options.EvmKeeper == EVMKeeper(nil) {
 		return sdkerrors.Wrap(sdkerrors.ErrLogic, "evm keeper is required for AnteHandler")
 	}
 	return nil
diff --git a/utils/json.go b/utils/json.go
index a1062e73..f43bd75c 100644
--- a/utils/json.go
+++ b/utils/json.go
@@ -36,7 +36,6 @@ func GenerateHash(json map[string]interface{}) (string, []byte, error) {
 		return "", nil, err
 	}
 
-	//cid, err := CIDFromJSONBytes(content)
 	cidString, err := CIDFromJSONBytesUsingIpldPrime(content)
 	if err != nil {
 		return "", nil, err
@@ -81,7 +80,7 @@ func CIDFromJSONBytesUsingIpldPrime(content []byte) (string, error) {
 	// This gathers together any parameters that might be needed when making a link.
 	// (For CIDs, the version, the codec, and the multihash type are all parameters we'll need.)
 	// Often, you can probably make this a constant for your whole application.
-	lp := cidlink.LinkPrototype{Prefix: cid.Prefix{
+	lp := cidlink.LinkPrototype{Prefix: cid.Prefix{ //nolint:golint
 		Version:  1,    // Usually '1'.
 		Codec:    0x71, // 0x71 means "dag-cbor" -- See the multicodecs table: https://github.com/multiformats/multicodec/
 		MhType:   0x12, // 0x12 means "sha2-256" -- See the multicodecs table: https://github.com/multiformats/multicodec/
diff --git a/utils/mnemonic.go b/utils/mnemonic.go
index 80dce1ac..4cb6591f 100644
--- a/utils/mnemonic.go
+++ b/utils/mnemonic.go
@@ -16,7 +16,7 @@ func GenerateMnemonic() (string, error) {
 		return "", err
 	}
 
-	mnemonic, err := bip39.NewMnemonic(entropySeed[:])
+	mnemonic, err := bip39.NewMnemonic(entropySeed)
 	if err != nil {
 		return "", err
 	}
diff --git a/utils/types.go b/utils/types.go
index 51e42acd..aaa03b78 100644
--- a/utils/types.go
+++ b/utils/types.go
@@ -12,10 +12,13 @@ import (
 	set "github.com/deckarep/golang-set"
 )
 
-func Int64ToBytes(num int64) []byte {
+func Int64ToBytes(num int64) ([]byte, error) {
 	buf := new(bytes.Buffer)
-	binary.Write(buf, binary.BigEndian, num)
-	return buf.Bytes()
+	if err := binary.Write(buf, binary.BigEndian, num); err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
 }
 
 func SetToSlice(set set.Set) []string {
diff --git a/x/evm/keeper/state_transition.go b/x/evm/keeper/state_transition.go
index 635e4df2..39ab08e4 100644
--- a/x/evm/keeper/state_transition.go
+++ b/x/evm/keeper/state_transition.go
@@ -215,7 +215,7 @@ func (k *Keeper) ApplyTransaction(ctx sdk.Context, tx *ethtypes.Transaction) (*t
 	// snapshot to contain the tx processing and post processing in same scope
 	var commit func()
 	tmpCtx := ctx
-	if k.hooks != nil {
+	if k.hooks != types.EvmHooks(nil) {
 		// Create a cache context to revert state when tx hooks fails,
 		// the cache context is only committed when both tx and hooks executed successfully.
 		// Didn't use `Snapshot` because the context stack has exponential complexity on certain operations,