diff --git a/x/mint/internal/keeper/keeper.go b/x/mint/internal/keeper/keeper.go
index 9fb918d7..5fd3ddfe 100644
--- a/x/mint/internal/keeper/keeper.go
+++ b/x/mint/internal/keeper/keeper.go
@@ -96,7 +96,7 @@ func (k Keeper) BondedRatio(ctx sdk.Context) sdk.Dec {
 
 // MintCoins implements an alias call to the underlying supply keeper's
 // MintCoins to be used in BeginBlocker.
-func (k Keeper) MintCoins(ctx sdk.Context, newCoins sdk.Coins) sdk.Error {
+func (k Keeper) MintCoins(ctx sdk.Context, newCoins sdk.Coins) error {
 	if newCoins.Empty() {
 		// skip as no coins need to be minted
 		return nil
@@ -106,6 +106,6 @@ func (k Keeper) MintCoins(ctx sdk.Context, newCoins sdk.Coins) sdk.Error {
 
 // AddCollectedFees implements an alias call to the underlying supply keeper's
 // AddCollectedFees to be used in BeginBlocker.
-func (k Keeper) AddCollectedFees(ctx sdk.Context, fees sdk.Coins) sdk.Error {
+func (k Keeper) AddCollectedFees(ctx sdk.Context, fees sdk.Coins) error {
 	return k.supplyKeeper.SendCoinsFromModuleToModule(ctx, types.ModuleName, k.feeCollectorName, fees)
 }
diff --git a/x/mint/internal/keeper/querier.go b/x/mint/internal/keeper/querier.go
index b2a89314..d9d17862 100644
--- a/x/mint/internal/keeper/querier.go
+++ b/x/mint/internal/keeper/querier.go
@@ -1,18 +1,17 @@
 package keeper
 
 import (
-	"fmt"
-
 	abci "github.com/tendermint/tendermint/abci/types"
 
 	"github.com/cosmos/cosmos-sdk/codec"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/unification-com/mainchain/x/mint/internal/types"
 )
 
 // NewQuerier returns a minting Querier handler.
 func NewQuerier(k Keeper) sdk.Querier {
-	return func(ctx sdk.Context, path []string, _ abci.RequestQuery) ([]byte, sdk.Error) {
+	return func(ctx sdk.Context, path []string, _ abci.RequestQuery) ([]byte, error) {
 		switch path[0] {
 		case types.QueryParameters:
 			return queryParams(ctx, k)
@@ -24,39 +23,39 @@ func NewQuerier(k Keeper) sdk.Querier {
 			return queryAnnualProvisions(ctx, k)
 
 		default:
-			return nil, sdk.ErrUnknownRequest(fmt.Sprintf("unknown minting query endpoint: %s", path[0]))
+			return nil, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unknown query path: %s", path[0])
 		}
 	}
 }
 
-func queryParams(ctx sdk.Context, k Keeper) ([]byte, sdk.Error) {
+func queryParams(ctx sdk.Context, k Keeper) ([]byte, error) {
 	params := k.GetParams(ctx)
 
 	res, err := codec.MarshalJSONIndent(k.cdc, params)
 	if err != nil {
-		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("failed to marshal JSON", err.Error()))
+		return nil, sdkerrors.Wrap(sdkerrors.ErrJSONMarshal, err.Error())
 	}
 
 	return res, nil
 }
 
-func queryInflation(ctx sdk.Context, k Keeper) ([]byte, sdk.Error) {
+func queryInflation(ctx sdk.Context, k Keeper) ([]byte, error) {
 	minter := k.GetMinter(ctx)
 
 	res, err := codec.MarshalJSONIndent(k.cdc, minter.Inflation)
 	if err != nil {
-		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("failed to marshal JSON", err.Error()))
+		return nil, sdkerrors.Wrap(sdkerrors.ErrJSONMarshal, err.Error())
 	}
 
 	return res, nil
 }
 
-func queryAnnualProvisions(ctx sdk.Context, k Keeper) ([]byte, sdk.Error) {
+func queryAnnualProvisions(ctx sdk.Context, k Keeper) ([]byte, error) {
 	minter := k.GetMinter(ctx)
 
 	res, err := codec.MarshalJSONIndent(k.cdc, minter.AnnualProvisions)
 	if err != nil {
-		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("failed to marshal JSON", err.Error()))
+		return nil, sdkerrors.Wrap(sdkerrors.ErrJSONMarshal, err.Error())
 	}
 
 	return res, nil
diff --git a/x/mint/internal/types/expected_keepers.go b/x/mint/internal/types/expected_keepers.go
index 564a0136..ea206191 100644
--- a/x/mint/internal/types/expected_keepers.go
+++ b/x/mint/internal/types/expected_keepers.go
@@ -18,7 +18,7 @@ type SupplyKeeper interface {
 	// TODO remove with genesis 2-phases refactor https://github.com/cosmos/cosmos-sdk/issues/2862
 	SetModuleAccount(sdk.Context, exported.ModuleAccountI)
 
-	SendCoinsFromModuleToAccount(ctx sdk.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) sdk.Error
-	SendCoinsFromModuleToModule(ctx sdk.Context, senderModule, recipientModule string, amt sdk.Coins) sdk.Error
-	MintCoins(ctx sdk.Context, name string, amt sdk.Coins) sdk.Error
+	SendCoinsFromModuleToAccount(ctx sdk.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) error
+	SendCoinsFromModuleToModule(ctx sdk.Context, senderModule, recipientModule string, amt sdk.Coins) error
+	MintCoins(ctx sdk.Context, name string, amt sdk.Coins) error
 }
diff --git a/x/mint/simulation/params.go b/x/mint/simulation/params.go
index b8a9fce2..a9b64bc3 100644
--- a/x/mint/simulation/params.go
+++ b/x/mint/simulation/params.go
@@ -21,22 +21,22 @@ const (
 // on the simulation
 func ParamChanges(r *rand.Rand) []simulation.ParamChange {
 	return []simulation.ParamChange{
-		simulation.NewSimParamChange(types.ModuleName, keyInflationRateChange, "",
+		simulation.NewSimParamChange(types.ModuleName, keyInflationRateChange,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenInflationRateChange(r))
 			},
 		),
-		simulation.NewSimParamChange(types.ModuleName, keyInflationMax, "",
+		simulation.NewSimParamChange(types.ModuleName, keyInflationMax,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenInflationMax(r))
 			},
 		),
-		simulation.NewSimParamChange(types.ModuleName, keyInflationMin, "",
+		simulation.NewSimParamChange(types.ModuleName, keyInflationMin,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenInflationMin(r))
 			},
 		),
-		simulation.NewSimParamChange(types.ModuleName, keyGoalBonded, "",
+		simulation.NewSimParamChange(types.ModuleName, keyGoalBonded,
 			func(r *rand.Rand) string {
 				return fmt.Sprintf("\"%s\"", GenGoalBonded(r))
 			},