diff --git a/config.go b/config.go
index a65962de..5de4e58f 100644
--- a/config.go
+++ b/config.go
@@ -162,7 +162,7 @@ func WithKeyPair[H Hash](priv PrivateKey, pub PublicKey) func(config *Config[H])
 }
 
 // WithGetKeyPair sets GetKeyPair.
-func WithGetKeyPair[H Hash](f func([]PublicKey) (int, PrivateKey, PublicKey)) func(config *Config[H]) {
+func WithGetKeyPair[H Hash](f func(pubs []PublicKey) (int, PrivateKey, PublicKey)) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.GetKeyPair = f
 	}
@@ -281,14 +281,14 @@ func WithCurrentBlockHash[H Hash](f func() H) func(config *Config[H]) {
 }
 
 // WithGetValidators sets GetValidators.
-func WithGetValidators[H Hash](f func(...Transaction[H]) []PublicKey) func(config *Config[H]) {
+func WithGetValidators[H Hash](f func(txs ...Transaction[H]) []PublicKey) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.GetValidators = f
 	}
 }
 
 // WithNewConsensusPayload sets NewConsensusPayload.
-func WithNewConsensusPayload[H Hash](f func(*Context[H], MessageType, any) ConsensusPayload[H]) func(config *Config[H]) {
+func WithNewConsensusPayload[H Hash](f func(ctx *Context[H], typ MessageType, msg any) ConsensusPayload[H]) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.NewConsensusPayload = f
 	}
@@ -309,14 +309,14 @@ func WithNewPrepareResponse[H Hash](f func(preparationHash H) PrepareResponse[H]
 }
 
 // WithNewChangeView sets NewChangeView.
-func WithNewChangeView[H Hash](f func(byte, ChangeViewReason, uint64) ChangeView) func(config *Config[H]) {
+func WithNewChangeView[H Hash](f func(newViewNumber byte, reason ChangeViewReason, ts uint64) ChangeView) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.NewChangeView = f
 	}
 }
 
 // WithNewCommit sets NewCommit.
-func WithNewCommit[H Hash](f func([]byte) Commit) func(config *Config[H]) {
+func WithNewCommit[H Hash](f func(signature []byte) Commit) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.NewCommit = f
 	}
@@ -337,14 +337,14 @@ func WithNewRecoveryMessage[H Hash](f func() RecoveryMessage[H]) func(config *Co
 }
 
 // WithVerifyPrepareRequest sets VerifyPrepareRequest.
-func WithVerifyPrepareRequest[H Hash](f func(ConsensusPayload[H]) error) func(config *Config[H]) {
+func WithVerifyPrepareRequest[H Hash](f func(prepareReq ConsensusPayload[H]) error) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.VerifyPrepareRequest = f
 	}
 }
 
 // WithVerifyPrepareResponse sets VerifyPrepareResponse.
-func WithVerifyPrepareResponse[H Hash](f func(ConsensusPayload[H]) error) func(config *Config[H]) {
+func WithVerifyPrepareResponse[H Hash](f func(prepareResp ConsensusPayload[H]) error) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
 		cfg.VerifyPrepareResponse = f
 	}
diff --git a/dbft.go b/dbft.go
index 39f72db9..db6cf851 100644
--- a/dbft.go
+++ b/dbft.go
@@ -1,6 +1,7 @@
 package dbft
 
 import (
+	"fmt"
 	"sync"
 	"time"
 
@@ -23,10 +24,10 @@ type (
 )
 
 // New returns new DBFT instance with specified H and A generic parameters
-// using provided options or nil if some of the options are missing or invalid.
+// using provided options or nil and error if some of the options are missing or invalid.
 // H and A generic parameters are used as hash and address representation for
 // dBFT consensus messages, blocks and transactions.
-func New[H Hash](options ...func(config *Config[H])) *DBFT[H] {
+func New[H Hash](options ...func(config *Config[H])) (*DBFT[H], error) {
 	cfg := defaultConfig[H]()
 
 	for _, option := range options {
@@ -34,7 +35,7 @@ func New[H Hash](options ...func(config *Config[H])) *DBFT[H] {
 	}
 
 	if err := checkConfig(cfg); err != nil {
-		return nil
+		return nil, fmt.Errorf("invalid config: %w", err)
 	}
 
 	d := &DBFT[H]{
@@ -45,7 +46,7 @@ func New[H Hash](options ...func(config *Config[H])) *DBFT[H] {
 		},
 	}
 
-	return d
+	return d, nil
 }
 
 func (d *DBFT[H]) addTransaction(tx Transaction[H]) {
diff --git a/dbft_test.go b/dbft_test.go
index 16ac328e..2adb1d52 100644
--- a/dbft_test.go
+++ b/dbft_test.go
@@ -43,7 +43,7 @@ func TestDBFT_OnStartPrimarySendPrepareRequest(t *testing.T) {
 
 	t.Run("backup sends nothing on start", func(t *testing.T) {
 		s.currHeight = 0
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 
 		service.Start(0)
 		require.Nil(t, s.tryRecv())
@@ -51,7 +51,7 @@ func TestDBFT_OnStartPrimarySendPrepareRequest(t *testing.T) {
 
 	t.Run("primary send PrepareRequest on start", func(t *testing.T) {
 		s.currHeight = 1
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 
 		service.Start(0)
 		p := s.tryRecv()
@@ -90,7 +90,7 @@ func TestDBFT_SingleNode(t *testing.T) {
 	s := newTestState(0, 1)
 
 	s.currHeight = 2
-	service := dbft.New[crypto.Uint256](s.getOptions()...)
+	service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 
 	service.Start(0)
 	p := s.tryRecv()
@@ -128,7 +128,7 @@ func TestDBFT_OnReceiveRequestSendResponse(t *testing.T) {
 
 	t.Run("receive request from primary", func(t *testing.T) {
 		s.currHeight = 4
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		txs := []testTx{1}
 		s.pool.Add(txs[0])
 
@@ -160,7 +160,7 @@ func TestDBFT_OnReceiveRequestSendResponse(t *testing.T) {
 
 	t.Run("change view on invalid tx", func(t *testing.T) {
 		s.currHeight = 4
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		txs := []testTx{10}
 
 		service.Start(0)
@@ -188,7 +188,7 @@ func TestDBFT_OnReceiveRequestSendResponse(t *testing.T) {
 
 	t.Run("receive invalid prepare request", func(t *testing.T) {
 		s.currHeight = 4
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		txs := []testTx{1, 2}
 		s.pool.Add(txs[0])
 
@@ -236,7 +236,7 @@ func TestDBFT_CommitOnTransaction(t *testing.T) {
 	s := newTestState(0, 4)
 	s.currHeight = 1
 
-	srv := dbft.New[crypto.Uint256](s.getOptions()...)
+	srv, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 	srv.Start(0)
 	require.Nil(t, s.tryRecv())
 
@@ -256,7 +256,7 @@ func TestDBFT_CommitOnTransaction(t *testing.T) {
 		privs:      s.privs,
 	}
 	s1.pool.Add(tx)
-	srv1 := dbft.New[crypto.Uint256](s1.getOptions()...)
+	srv1, _ := dbft.New[crypto.Uint256](s1.getOptions()...)
 	srv1.Start(0)
 	srv1.OnReceive(req)
 	srv1.OnReceive(s1.getPrepareResponse(1, req.Hash()))
@@ -278,7 +278,7 @@ func TestDBFT_OnReceiveCommit(t *testing.T) {
 	s := newTestState(2, 4)
 	t.Run("send commit after enough responses", func(t *testing.T) {
 		s.currHeight = 1
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		service.Start(0)
 
 		req := s.tryRecv()
@@ -338,7 +338,7 @@ func TestDBFT_OnReceiveRecoveryRequest(t *testing.T) {
 	s := newTestState(2, 4)
 	t.Run("send recovery message", func(t *testing.T) {
 		s.currHeight = 1
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		service.Start(0)
 
 		req := s.tryRecv()
@@ -360,7 +360,7 @@ func TestDBFT_OnReceiveRecoveryRequest(t *testing.T) {
 		require.Equal(t, dbft.RecoveryMessageType, rm.Type())
 
 		other := s.copyWithIndex(3)
-		srv2 := dbft.New[crypto.Uint256](other.getOptions()...)
+		srv2, _ := dbft.New[crypto.Uint256](other.getOptions()...)
 		srv2.Start(0)
 		srv2.OnReceive(rm)
 
@@ -383,7 +383,7 @@ func TestDBFT_OnReceiveChangeView(t *testing.T) {
 	s := newTestState(2, 4)
 	t.Run("change view correctly", func(t *testing.T) {
 		s.currHeight = 6
-		service := dbft.New[crypto.Uint256](s.getOptions()...)
+		service, _ := dbft.New[crypto.Uint256](s.getOptions()...)
 		service.Start(0)
 
 		resp := s.getChangeView(1, 1)
@@ -410,7 +410,8 @@ func TestDBFT_OnReceiveChangeView(t *testing.T) {
 
 func TestDBFT_Invalid(t *testing.T) {
 	t.Run("without keys", func(t *testing.T) {
-		require.Nil(t, dbft.New[crypto.Uint256]())
+		_, err := dbft.New[crypto.Uint256]()
+		require.Error(t, err)
 	})
 
 	priv, pub := crypto.Generate(rand.Reader)
@@ -419,85 +420,98 @@ func TestDBFT_Invalid(t *testing.T) {
 
 	opts := []func(*dbft.Config[crypto.Uint256]){dbft.WithKeyPair[crypto.Uint256](priv, pub)}
 	t.Run("without Timer", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithTimer[crypto.Uint256](timer.New()))
 	t.Run("without CurrentHeight", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithCurrentHeight[crypto.Uint256](func() uint32 { return 0 }))
 	t.Run("without CurrentBlockHash", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithCurrentBlockHash[crypto.Uint256](func() crypto.Uint256 { return crypto.Uint256{} }))
 	t.Run("without GetValidators", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithGetValidators[crypto.Uint256](func(...dbft.Transaction[crypto.Uint256]) []dbft.PublicKey {
 		return []dbft.PublicKey{pub}
 	}))
 	t.Run("without NewBlockFromContext", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewBlockFromContext[crypto.Uint256](func(_ *dbft.Context[crypto.Uint256]) dbft.Block[crypto.Uint256] {
 		return nil
 	}))
 	t.Run("without NewConsensusPayload", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewConsensusPayload[crypto.Uint256](func(_ *dbft.Context[crypto.Uint256], _ dbft.MessageType, _ any) dbft.ConsensusPayload[crypto.Uint256] {
 		return nil
 	}))
 	t.Run("without NewPrepareRequest", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewPrepareRequest[crypto.Uint256](func(uint64, uint64, []crypto.Uint256) dbft.PrepareRequest[crypto.Uint256] {
 		return nil
 	}))
 	t.Run("without NewPrepareResponse", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewPrepareResponse[crypto.Uint256](func(crypto.Uint256) dbft.PrepareResponse[crypto.Uint256] {
 		return nil
 	}))
 	t.Run("without NewChangeView", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewChangeView[crypto.Uint256](func(byte, dbft.ChangeViewReason, uint64) dbft.ChangeView {
 		return nil
 	}))
 	t.Run("without NewCommit", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewCommit[crypto.Uint256](func([]byte) dbft.Commit {
 		return nil
 	}))
 	t.Run("without NewRecoveryRequest", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewRecoveryRequest[crypto.Uint256](func(uint64) dbft.RecoveryRequest {
 		return nil
 	}))
 	t.Run("without NewRecoveryMessage", func(t *testing.T) {
-		require.Nil(t, dbft.New(opts...))
+		_, err := dbft.New(opts...)
+		require.Error(t, err)
 	})
 
 	opts = append(opts, dbft.WithNewRecoveryMessage[crypto.Uint256](func() dbft.RecoveryMessage[crypto.Uint256] {
 		return nil
 	}))
 	t.Run("with all defaults", func(t *testing.T) {
-		d := dbft.New(opts...)
+		d, err := dbft.New(opts...)
+		require.NoError(t, err)
 		require.NotNil(t, d)
 		require.NotNil(t, d.Config.RequestTx)
 		require.NotNil(t, d.Config.GetTx)
@@ -526,19 +540,19 @@ func TestDBFT_Invalid(t *testing.T) {
 func TestDBFT_FourGoodNodesDeadlock(t *testing.T) {
 	r0 := newTestState(0, 4)
 	r0.currHeight = 4
-	s0 := dbft.New[crypto.Uint256](r0.getOptions()...)
+	s0, _ := dbft.New[crypto.Uint256](r0.getOptions()...)
 	s0.Start(0)
 
 	r1 := r0.copyWithIndex(1)
-	s1 := dbft.New[crypto.Uint256](r1.getOptions()...)
+	s1, _ := dbft.New[crypto.Uint256](r1.getOptions()...)
 	s1.Start(0)
 
 	r2 := r0.copyWithIndex(2)
-	s2 := dbft.New[crypto.Uint256](r2.getOptions()...)
+	s2, _ := dbft.New[crypto.Uint256](r2.getOptions()...)
 	s2.Start(0)
 
 	r3 := r0.copyWithIndex(3)
-	s3 := dbft.New[crypto.Uint256](r3.getOptions()...)
+	s3, _ := dbft.New[crypto.Uint256](r3.getOptions()...)
 	s3.Start(0)
 
 	// Step 1. The primary (at view 0) replica 1 sends the PrepareRequest message.
diff --git a/internal/consensus/consensus.go b/internal/consensus/consensus.go
index 2db7c88c..e264d884 100644
--- a/internal/consensus/consensus.go
+++ b/internal/consensus/consensus.go
@@ -17,7 +17,7 @@ func New(logger *zap.Logger, key dbft.PrivateKey, pub dbft.PublicKey,
 	currentHeight func() uint32,
 	currentBlockHash func() crypto.Uint256,
 	getValidators func(...dbft.Transaction[crypto.Uint256]) []dbft.PublicKey,
-	verifyPayload func(consensusPayload dbft.ConsensusPayload[crypto.Uint256]) error) *dbft.DBFT[crypto.Uint256] {
+	verifyPayload func(consensusPayload dbft.ConsensusPayload[crypto.Uint256]) error) (*dbft.DBFT[crypto.Uint256], error) {
 	return dbft.New[crypto.Uint256](
 		dbft.WithTimer[crypto.Uint256](timer.New()),
 		dbft.WithLogger[crypto.Uint256](logger),
diff --git a/internal/simulation/main.go b/internal/simulation/main.go
index 3c857727..4587b358 100644
--- a/internal/simulation/main.go
+++ b/internal/simulation/main.go
@@ -121,7 +121,8 @@ func initSimNode(nodes []*simNode, i int, log *zap.Logger) error {
 		cluster:  nodes,
 	}
 
-	nodes[i].d = consensus.New(nodes[i].log, key, pub, nodes[i].pool.Get,
+	var err error
+	nodes[i].d, err = consensus.New(nodes[i].log, key, pub, nodes[i].pool.Get,
 		nodes[i].pool.GetVerified,
 		nodes[i].Broadcast,
 		nodes[i].ProcessBlock,
@@ -130,9 +131,8 @@ func initSimNode(nodes []*simNode, i int, log *zap.Logger) error {
 		nodes[i].GetValidators,
 		nodes[i].VerifyPayload,
 	)
-
-	if nodes[i].d == nil {
-		return errors.New("can't initialize dBFT")
+	if err != nil {
+		return fmt.Errorf("failed to initialize dBFT: %w", err)
 	}
 
 	nodes[i].addTx(*txCount)