diff --git a/pkg/auth/auth.go b/pkg/auth/auth.go
index 70e11ff..be42186 100644
--- a/pkg/auth/auth.go
+++ b/pkg/auth/auth.go
@@ -24,13 +24,13 @@ func Authenticate(req *http.Request, s *terraform.State) (ok bool, err error) {
 
 	var authenticator Authenticator
 	switch backend {
-	case "basic":
+	case basic.Name:
 		viper.SetDefault("auth_basic_enabled", true)
 		if !viper.GetBool("auth_basic_enabled") {
 			return false, fmt.Errorf("basic auth is not enabled")
 		}
 		authenticator = basic.NewBasicAuth()
-	case "jwt":
+	case jwt.Name:
 		issuerURL := viper.GetString("auth_jwt_oidc_issuer_url")
 		if addr := viper.GetString("vault_addr"); issuerURL != "" && addr != "" {
 			issuerURL = fmt.Sprintf("%s/v1/identity/oidc", addr)
diff --git a/pkg/auth/basic/basic.go b/pkg/auth/basic/basic.go
index edff74c..7506e40 100644
--- a/pkg/auth/basic/basic.go
+++ b/pkg/auth/basic/basic.go
@@ -7,6 +7,8 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "basic"
+
 type BasicAuth struct{}
 
 func NewBasicAuth() *BasicAuth {
@@ -14,7 +16,7 @@ func NewBasicAuth() *BasicAuth {
 }
 
 func (l *BasicAuth) GetName() string {
-	return "basic"
+	return Name
 }
 
 func (b *BasicAuth) Authenticate(secret string, s *terraform.State) (bool, error) {
diff --git a/pkg/auth/jwt/jwt.go b/pkg/auth/jwt/jwt.go
index 399e467..cd785e7 100644
--- a/pkg/auth/jwt/jwt.go
+++ b/pkg/auth/jwt/jwt.go
@@ -8,6 +8,8 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "jwt"
+
 type JWTAuth struct {
 	issuerURL string
 }
@@ -19,7 +21,7 @@ func NewJWTAuth(issuerURL string) *JWTAuth {
 }
 
 func (l *JWTAuth) GetName() string {
-	return "jwt"
+	return Name
 }
 
 func (b *JWTAuth) Authenticate(secret string, s *terraform.State) (bool, error) {
diff --git a/pkg/kms/local/local.go b/pkg/kms/local/local.go
index c50a8ef..b067ced 100644
--- a/pkg/kms/local/local.go
+++ b/pkg/kms/local/local.go
@@ -9,6 +9,8 @@ import (
 	"io"
 )
 
+const Name = "local"
+
 type KMS struct {
 	cipher cipher.AEAD
 }
@@ -34,7 +36,7 @@ func GenerateKey() (string, error) {
 }
 
 func (v *KMS) GetName() string {
-	return "local"
+	return Name
 }
 
 func (s *KMS) Encrypt(d []byte) ([]byte, error) {
diff --git a/pkg/kms/transit/transit.go b/pkg/kms/transit/transit.go
index f6bc5b8..b22c5d1 100644
--- a/pkg/kms/transit/transit.go
+++ b/pkg/kms/transit/transit.go
@@ -7,6 +7,8 @@ import (
 	vaultclient "github.com/nimbolus/terraform-backend/pkg/client/vault"
 )
 
+const Name = "transit"
+
 type VaultTransit struct {
 	engine string
 	key    string
@@ -25,7 +27,7 @@ func NewVaultTransit(engine string, key string) (*VaultTransit, error) {
 }
 
 func (v *VaultTransit) GetName() string {
-	return "transit"
+	return Name
 }
 
 func (v *VaultTransit) Encrypt(d []byte) ([]byte, error) {
diff --git a/pkg/lock/local/local.go b/pkg/lock/local/local.go
index 049a243..784681a 100644
--- a/pkg/lock/local/local.go
+++ b/pkg/lock/local/local.go
@@ -6,6 +6,8 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "local"
+
 type Lock struct {
 	mutex sync.Mutex
 	db    map[string][]byte
@@ -18,7 +20,7 @@ func NewLock() *Lock {
 }
 
 func (l *Lock) GetName() string {
-	return "local"
+	return Name
 }
 
 func (l *Lock) Lock(s *terraform.State) (bool, error) {
diff --git a/pkg/lock/postgres/postgres.go b/pkg/lock/postgres/postgres.go
index 2847d01..d61a2f5 100644
--- a/pkg/lock/postgres/postgres.go
+++ b/pkg/lock/postgres/postgres.go
@@ -3,13 +3,14 @@ package postgres
 import (
 	"context"
 	"database/sql"
-	"fmt"
 	"time"
 
 	pgclient "github.com/nimbolus/terraform-backend/pkg/client/postgres"
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "postgres"
+
 type Lock struct {
 	db *pgclient.Client
 }
@@ -26,7 +27,7 @@ func NewLock() (*Lock, error) {
 }
 
 func (l *Lock) GetName() string {
-	return "pg"
+	return Name
 }
 
 func (l *Lock) Lock(s *terraform.State) (bool, error) {
@@ -40,9 +41,9 @@ func (l *Lock) Lock(s *terraform.State) (bool, error) {
 
 	defer tx.Rollback()
 
-	var lockData []byte
+	var lock []byte
 
-	if err := tx.QueryRow(`SELECT lock_data FROM `+l.db.GetLocksTableName()+` WHERE state_id = $1`, s.ID).Scan(&lockData); err != nil {
+	if err := tx.QueryRow(`SELECT lock_data FROM `+l.db.GetLocksTableName()+` WHERE state_id = $1`, s.ID).Scan(&lock); err != nil {
 		if err == sql.ErrNoRows {
 			if _, err := tx.Exec(`INSERT INTO locks (state_id, lock_data) VALUES ($1, $2)`, s.ID, s.Lock); err != nil {
 				return false, err
@@ -58,12 +59,14 @@ func (l *Lock) Lock(s *terraform.State) (bool, error) {
 		return false, err
 	}
 
-	if string(lockData) == string(s.Lock) {
+	if string(lock) == string(s.Lock) {
 		// you already have the lock
 		return true, nil
 	}
 
-	return false, fmt.Errorf("lock already taken for id %s: %s", s.ID, string(lockData))
+	s.Lock = lock
+
+	return false, nil
 }
 
 func (l *Lock) Unlock(s *terraform.State) (bool, error) {
@@ -77,18 +80,18 @@ func (l *Lock) Unlock(s *terraform.State) (bool, error) {
 
 	defer tx.Rollback()
 
-	var lockData []byte
+	var lock []byte
 
-	if err := tx.QueryRow(`SELECT lock_data FROM `+l.db.GetLocksTableName()+` WHERE state_id = $1`, s.ID).Scan(&lockData); err != nil {
+	if err := tx.QueryRow(`SELECT lock_data FROM `+l.db.GetLocksTableName()+` WHERE state_id = $1`, s.ID).Scan(&lock); err != nil {
 		if err == sql.ErrNoRows {
-			return false, fmt.Errorf("no lock for id %s found", s.ID)
+			return false, nil
 		}
 
 		return false, err
 	}
 
-	if string(lockData) != string(s.Lock) {
-		return false, fmt.Errorf("lock mismatch for id %s", s.ID)
+	if string(lock) != string(s.Lock) {
+		return false, nil
 	}
 
 	if _, err := tx.Exec(`DELETE FROM `+l.db.GetLocksTableName()+` WHERE state_id = $1 AND lock_data = $2`, s.ID, s.Lock); err != nil {
diff --git a/pkg/lock/postgres/postgres_test.go b/pkg/lock/postgres/postgres_test.go
index c180c75..c724b56 100644
--- a/pkg/lock/postgres/postgres_test.go
+++ b/pkg/lock/postgres/postgres_test.go
@@ -6,9 +6,15 @@ package postgres
 import (
 	"testing"
 
+	"github.com/spf13/viper"
+
 	"github.com/nimbolus/terraform-backend/pkg/lock/util"
 )
 
+func init() {
+	viper.AutomaticEnv()
+}
+
 func TestLock(t *testing.T) {
 	l, err := NewLock()
 	if err != nil {
diff --git a/pkg/lock/redis/redis.go b/pkg/lock/redis/redis.go
index 72b7eed..277ab8e 100644
--- a/pkg/lock/redis/redis.go
+++ b/pkg/lock/redis/redis.go
@@ -19,7 +19,10 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
-const lockKey = "terraform-backend-state-lock"
+const (
+	Name    = "redis"
+	lockKey = "terraform-backend-state-lock"
+)
 
 type Lock struct {
 	pool   *redigo.Pool
@@ -39,7 +42,7 @@ func NewLock() *Lock {
 }
 
 func (r *Lock) GetName() string {
-	return "redis"
+	return Name
 }
 
 func (r *Lock) Lock(s *terraform.State) (locked bool, err error) {
diff --git a/pkg/server/kms.go b/pkg/server/kms.go
index 2fc251e..ac78662 100644
--- a/pkg/server/kms.go
+++ b/pkg/server/kms.go
@@ -12,11 +12,11 @@ import (
 )
 
 func GetKMS() (k kms.KMS, err error) {
-	viper.SetDefault("kms_backend", "local")
+	viper.SetDefault("kms_backend", local.Name)
 	backend := viper.GetString("kms_backend")
 
 	switch backend {
-	case "local":
+	case local.Name:
 		key := viper.GetString("kms_key")
 		if key == "" {
 			key, _ = local.GenerateKey()
@@ -38,7 +38,7 @@ func GetKMS() (k kms.KMS, err error) {
 		}
 
 		k, err = local.NewKMS(key)
-	case "transit":
+	case transit.Name:
 		k, err = transit.NewVaultTransit(viper.GetString("kms_transit_engine"), viper.GetString("kms_transit_key"))
 	default:
 		return nil, fmt.Errorf("failed to initialize KMS backend %s: %v", backend, err)
diff --git a/pkg/server/locker.go b/pkg/server/locker.go
index dee0ccb..81c32c2 100644
--- a/pkg/server/locker.go
+++ b/pkg/server/locker.go
@@ -12,15 +12,15 @@ import (
 )
 
 func GetLocker() (l lock.Locker, err error) {
-	viper.SetDefault("lock_backend", "local")
+	viper.SetDefault("lock_backend", local.Name)
 	backend := viper.GetString("lock_backend")
 
 	switch backend {
-	case "local":
+	case local.Name:
 		l = local.NewLock()
-	case "redis":
+	case redis.Name:
 		l = redis.NewLock()
-	case "postgres":
+	case postgres.Name:
 		l, err = postgres.NewLock()
 	default:
 		err = fmt.Errorf("backend is not implemented")
diff --git a/pkg/server/storage.go b/pkg/server/storage.go
index c4d02f0..75ba09d 100644
--- a/pkg/server/storage.go
+++ b/pkg/server/storage.go
@@ -11,14 +11,14 @@ import (
 )
 
 func GetStorage() (s storage.Storage, err error) {
-	viper.SetDefault("storage_backend", "fs")
+	viper.SetDefault("storage_backend", filesystem.Name)
 	backend := viper.GetString("storage_backend")
 
 	switch backend {
-	case "fs":
+	case filesystem.Name:
 		viper.SetDefault("storage_fs_dir", "./states")
 		s, err = filesystem.NewFileSystemStorage(viper.GetString("storage_fs_dir"))
-	case "s3":
+	case s3.Name:
 		viper.SetDefault("storage_s3_endpoint", "s3.amazonaws.com")
 		viper.SetDefault("storage_s3_use_ssl", true)
 		viper.SetDefault("storage_s3_bucket", "terraform-state")
diff --git a/pkg/storage/filesystem/filesystem.go b/pkg/storage/filesystem/filesystem.go
index 14907f6..c0776f0 100644
--- a/pkg/storage/filesystem/filesystem.go
+++ b/pkg/storage/filesystem/filesystem.go
@@ -8,6 +8,8 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "fs"
+
 type FileSystemStorage struct {
 	directory string
 }
@@ -24,7 +26,7 @@ func NewFileSystemStorage(directory string) (*FileSystemStorage, error) {
 }
 
 func (f *FileSystemStorage) GetName() string {
-	return "file"
+	return Name
 }
 
 func (f *FileSystemStorage) SaveState(s *terraform.State) error {
diff --git a/pkg/storage/s3/s3.go b/pkg/storage/s3/s3.go
index aaba9b8..5b2535c 100644
--- a/pkg/storage/s3/s3.go
+++ b/pkg/storage/s3/s3.go
@@ -11,6 +11,8 @@ import (
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+const Name = "s3"
+
 type S3Storage struct {
 	client *minio.Client
 	bucket string
@@ -38,7 +40,7 @@ func NewS3Storage(endpoint, bucket, accessKey, secretKey string, useSSL bool) (*
 }
 
 func (s *S3Storage) GetName() string {
-	return "s3"
+	return Name
 }
 
 func (s *S3Storage) SaveState(state *terraform.State) error {