diff --git a/x/slashing/CHANGELOG.md b/x/slashing/CHANGELOG.md
index 81a7018057d4..121c64c1b0a5 100644
--- a/x/slashing/CHANGELOG.md
+++ b/x/slashing/CHANGELOG.md
@@ -35,6 +35,9 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking Changes
 
+* [#20026](https://github.com/cosmos/cosmos-sdk/pull/20026) Removal of the Address.String() method and related changes:
+    * `Migrate` now takes a `ValidatorAddressCodec` as argument.
+    * `Migrator` has a new field of `ValidatorAddressCodec` type.
 * [#16441](https://github.com/cosmos/cosmos-sdk/pull/16441) Params state is migrated to collections. `GetParams` has been removed.
 * [#17023](https://github.com/cosmos/cosmos-sdk/pull/17023) Use collections for `ValidatorSigningInfo`:
     * remove `Keeper`: `SetValidatorSigningInfo`, `GetValidatorSigningInfo`, `IterateValidatorSigningInfos`
diff --git a/x/slashing/keeper/migrations.go b/x/slashing/keeper/migrations.go
index 8dde29ff7707..9f00003d315b 100644
--- a/x/slashing/keeper/migrations.go
+++ b/x/slashing/keeper/migrations.go
@@ -3,6 +3,7 @@ package keeper
 import (
 	"context"
 
+	"cosmossdk.io/core/address"
 	v4 "cosmossdk.io/x/slashing/migrations/v4"
 
 	"github.com/cosmos/cosmos-sdk/runtime"
@@ -10,12 +11,16 @@ import (
 
 // Migrator is a struct for handling in-place store migrations.
 type Migrator struct {
-	keeper Keeper
+	keeper   Keeper
+	valCodec address.ValidatorAddressCodec
 }
 
 // NewMigrator returns a new Migrator.
-func NewMigrator(keeper Keeper) Migrator {
-	return Migrator{keeper: keeper}
+func NewMigrator(keeper Keeper, valCodec address.ValidatorAddressCodec) Migrator {
+	return Migrator{
+		keeper:   keeper,
+		valCodec: valCodec,
+	}
 }
 
 // Migrate1to2 migrates from version 1 to 2.
@@ -40,5 +45,5 @@ func (m Migrator) Migrate3to4(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	return v4.Migrate(ctx, m.keeper.cdc, store, params)
+	return v4.Migrate(ctx, m.keeper.cdc, store, params, m.valCodec)
 }
diff --git a/x/slashing/migrations/v4/migrate.go b/x/slashing/migrations/v4/migrate.go
index f81566996e68..331068c32824 100644
--- a/x/slashing/migrations/v4/migrate.go
+++ b/x/slashing/migrations/v4/migrate.go
@@ -6,6 +6,7 @@ import (
 	"github.com/bits-and-blooms/bitset"
 	gogotypes "github.com/cosmos/gogoproto/types"
 
+	"cosmossdk.io/core/address"
 	"cosmossdk.io/errors"
 	storetypes "cosmossdk.io/store/types"
 	"cosmossdk.io/x/slashing/types"
@@ -17,12 +18,15 @@ import (
 // Migrate migrates state to consensus version 4. Specifically, the migration
 // deletes all existing validator bitmap entries and replaces them with a real
 // "chunked" bitmap.
-func Migrate(ctx context.Context, cdc codec.BinaryCodec, store storetypes.KVStore, params types.Params) error {
+func Migrate(ctx context.Context, cdc codec.BinaryCodec, store storetypes.KVStore, params types.Params, addressCodec address.ValidatorAddressCodec) error {
 	// Get all the missed blocks for each validator, based on the existing signing
 	// info.
 	var missedBlocks []types.ValidatorMissedBlocks
 	iterateValidatorSigningInfos(ctx, cdc, store, func(addr sdk.ConsAddress, info types.ValidatorSigningInfo) (stop bool) {
-		bechAddr := addr.String()
+		bechAddr, err := addressCodec.BytesToString(addr)
+		if err != nil {
+			return true
+		}
 		localMissedBlocks := GetValidatorMissedBlocks(ctx, cdc, store, addr, params)
 
 		missedBlocks = append(missedBlocks, types.ValidatorMissedBlocks{
diff --git a/x/slashing/migrations/v4/migrate_test.go b/x/slashing/migrations/v4/migrate_test.go
index 41d8995af6e4..84fe79544624 100644
--- a/x/slashing/migrations/v4/migrate_test.go
+++ b/x/slashing/migrations/v4/migrate_test.go
@@ -12,6 +12,7 @@ import (
 	v4 "cosmossdk.io/x/slashing/migrations/v4"
 	slashingtypes "cosmossdk.io/x/slashing/types"
 
+	"github.com/cosmos/cosmos-sdk/codec/address"
 	codectestutil "github.com/cosmos/cosmos-sdk/codec/testutil"
 	"github.com/cosmos/cosmos-sdk/testutil"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -27,9 +28,12 @@ func TestMigrate(t *testing.T) {
 	ctx := testutil.DefaultContext(storeKey, tKey)
 	store := ctx.KVStore(storeKey)
 	params := slashingtypes.Params{SignedBlocksWindow: 100}
+	valCodec := address.NewBech32Codec("cosmosvalcons")
+	consStrAddr, err := valCodec.BytesToString(consAddr)
+	require.NoError(t, err)
 
 	// store old signing info and bitmap entries
-	bz := cdc.MustMarshal(&slashingtypes.ValidatorSigningInfo{Address: consAddr.String()})
+	bz := cdc.MustMarshal(&slashingtypes.ValidatorSigningInfo{Address: consStrAddr})
 	store.Set(v4.ValidatorSigningInfoKey(consAddr), bz)
 
 	for i := int64(0); i < params.SignedBlocksWindow; i++ {
@@ -39,7 +43,7 @@ func TestMigrate(t *testing.T) {
 		store.Set(v4.ValidatorMissedBlockBitArrayKey(consAddr, i), bz)
 	}
 
-	err := v4.Migrate(ctx, cdc, store, params)
+	err = v4.Migrate(ctx, cdc, store, params, valCodec)
 	require.NoError(t, err)
 
 	for i := int64(0); i < params.SignedBlocksWindow; i++ {
diff --git a/x/slashing/module.go b/x/slashing/module.go
index dab442d3860d..c5ae4fef1919 100644
--- a/x/slashing/module.go
+++ b/x/slashing/module.go
@@ -103,7 +103,7 @@ func (am AppModule) RegisterServices(registrar grpc.ServiceRegistrar) error {
 
 // RegisterMigrations registers module migrations.
 func (am AppModule) RegisterMigrations(mr appmodule.MigrationRegistrar) error {
-	m := keeper.NewMigrator(am.keeper)
+	m := keeper.NewMigrator(am.keeper, am.stakingKeeper.ValidatorAddressCodec())
 
 	if err := mr.Register(types.ModuleName, 1, m.Migrate1to2); err != nil {
 		return fmt.Errorf("failed to migrate x/%s from version 1 to 2: %w", types.ModuleName, err)
diff --git a/x/slashing/simulation/proposals.go b/x/slashing/simulation/proposals.go
index 5d37412ad821..1ea39d97f19a 100644
--- a/x/slashing/simulation/proposals.go
+++ b/x/slashing/simulation/proposals.go
@@ -33,10 +33,15 @@ func ProposalMsgs() []simtypes.WeightedProposalMsg {
 }
 
 // SimulateMsgUpdateParams returns a random MsgUpdateParams
-func SimulateMsgUpdateParams(r *rand.Rand, _ []simtypes.Account, _ coreaddress.Codec) (sdk.Msg, error) {
+func SimulateMsgUpdateParams(r *rand.Rand, _ []simtypes.Account, ac coreaddress.Codec) (sdk.Msg, error) {
 	// use the default gov module account address as authority
 	var authority sdk.AccAddress = address.Module("gov")
 
+	authorityAddr, err := ac.BytesToString(authority)
+	if err != nil {
+		return nil, err
+	}
+
 	params := types.DefaultParams()
 	params.DowntimeJailDuration = time.Duration(simtypes.RandTimestamp(r).UnixNano())
 	params.SignedBlocksWindow = int64(simtypes.RandIntBetween(r, 1, 1000))
@@ -45,7 +50,7 @@ func SimulateMsgUpdateParams(r *rand.Rand, _ []simtypes.Account, _ coreaddress.C
 	params.SlashFractionDowntime = sdkmath.LegacyNewDecWithPrec(int64(simtypes.RandIntBetween(r, 1, 100)), 2)
 
 	return &types.MsgUpdateParams{
-		Authority: authority.String(),
+		Authority: authorityAddr,
 		Params:    params,
 	}, nil
 }
diff --git a/x/slashing/simulation/proposals_test.go b/x/slashing/simulation/proposals_test.go
index 6a67de33fd29..d2b553964a00 100644
--- a/x/slashing/simulation/proposals_test.go
+++ b/x/slashing/simulation/proposals_test.go
@@ -12,7 +12,6 @@ import (
 	"cosmossdk.io/x/slashing/types"
 
 	codectestutil "github.com/cosmos/cosmos-sdk/codec/testutil"
-	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
 	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
 )
@@ -21,6 +20,7 @@ func TestProposalMsgs(t *testing.T) {
 	// initialize parameters
 	s := rand.NewSource(1)
 	r := rand.New(s)
+	ac := codectestutil.CodecOptions{}.GetAddressCodec()
 
 	accounts := simtypes.RandomAccounts(r, 3)
 
@@ -34,12 +34,15 @@ func TestProposalMsgs(t *testing.T) {
 	assert.Equal(t, simulation.OpWeightMsgUpdateParams, w0.AppParamsKey())
 	assert.Equal(t, simulation.DefaultWeightMsgUpdateParams, w0.DefaultWeight())
 
-	msg, err := w0.MsgSimulatorFn()(r, accounts, codectestutil.CodecOptions{}.GetAddressCodec())
+	msg, err := w0.MsgSimulatorFn()(r, accounts, ac)
 	assert.NilError(t, err)
 	msgUpdateParams, ok := msg.(*types.MsgUpdateParams)
 	assert.Assert(t, ok)
 
-	assert.Equal(t, sdk.AccAddress(address.Module("gov")).String(), msgUpdateParams.Authority)
+	moduleAddr, err := ac.BytesToString(address.Module("gov"))
+	assert.NilError(t, err)
+
+	assert.Equal(t, moduleAddr, msgUpdateParams.Authority)
 	assert.Equal(t, int64(905), msgUpdateParams.Params.SignedBlocksWindow)
 	assert.DeepEqual(t, sdkmath.LegacyNewDecWithPrec(7, 2), msgUpdateParams.Params.MinSignedPerWindow)
 	assert.DeepEqual(t, sdkmath.LegacyNewDecWithPrec(60, 2), msgUpdateParams.Params.SlashFractionDoubleSign)