diff --git a/package.json b/package.json
index a9ad4b24..4fa90026 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "signales",
-  "version": "2.0.4",
+  "version": "2.0.5",
   "description": "Highly configurable logging utility",
   "license": "MIT",
   "repository": "anru/signales",
@@ -39,7 +39,7 @@
   "devDependencies": {
     "@types/node": "^11.11.3",
     "tsd": "^0.14.0",
-    "typescript": "^4.1.3"
+    "typescript": "^4.2.3"
   },
   "author": {
     "name": "Klaus Sinani",
diff --git a/src/logger-types.ts b/src/logger-types.ts
index 89d84d2d..855181d9 100644
--- a/src/logger-types.ts
+++ b/src/logger-types.ts
@@ -1,8 +1,8 @@
 'use strict';
 import figures from 'figures'
-import type { DefaultLogTypes, LoggerTypesConf } from './types'
+import type { DefaultLoggerTypes } from './types'
 
-const logTypes: LoggerTypesConf<DefaultLogTypes> = {
+const logTypes: DefaultLoggerTypes = {
   error: {
     badge: figures.cross,
     color: 'red',
diff --git a/src/main.ts b/src/main.ts
index 761813f0..d1704749 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -10,7 +10,7 @@ import type {
   ScopeFormatter, DefaultLogLevels,
 } from './types'
 
-export type SignaleEntrypoint = typeof Signale & { Signale: SignaleConstructor}
+export type SignaleEntrypoint = typeof Signale & { Signale: SignaleConstructor }
 
 const signale: SignaleEntrypoint = Object.assign(new Signale(), {
   Signale,
@@ -25,8 +25,9 @@ export {
   Signales,
 }
 
-// utility type
-export type SignaleConstructorOptions<T extends string = DefaultLogTypes, L extends string = DefaultLogLevels> = ConstructorOptions<T, L>
+// type for backward compartibility
+// same as ConstructorOptions
+export type SignaleConstructorOptions<T extends string = never, L extends string = never> = ConstructorOptions<T, L>
 
 // re-export types
 export {
@@ -35,7 +36,10 @@ export {
   InstanceConfiguration,
   LoggerFunction,
   LoggerTypesConf,
-  ScopeFormatter
+  ScopeFormatter,
+  DefaultLogTypes,
+  DefaultLogLevels,
+  ConstructorOptions,
 }
 
 export default signale
diff --git a/src/signale.ts b/src/signale.ts
index 0ab51f68..dc995123 100644
--- a/src/signale.ts
+++ b/src/signale.ts
@@ -14,6 +14,7 @@ import {
   DefaultLogTypes, InstanceConfiguration,
   LoggerConfiguration, LoggerFunction,
   LoggerTypesConf,
+  DefaultLoggerTypes,
   DefaultLogLevels, ScopeFormatter, Secrets
 } from './types'
 
@@ -52,17 +53,17 @@ function barsScopeFormatter(scopes: string[]): string {
   return scopes.map(scope => `[${scope}]`).join(' ')
 }
 
-class SignaleImpl<T extends string = DefaultLogTypes, L extends string = DefaultLogLevels> {
+class SignaleImpl<T extends string = never, L extends string = never> {
   _interactive: boolean
   _config: InstanceConfiguration
-  _customTypes: Partial<LoggerTypesConf<T, L>>
-  _customLogLevels: Record<string, number>
+  _customTypes: LoggerTypesConf<T, L> & Partial<LoggerTypesConf<DefaultLogTypes, L>>
+  _customLogLevels: Partial<Record<DefaultLogLevels, number>> & Record<L, number>
   _logLevels: Record<string, number>
   _disabled: boolean
   _scopeName: string | string[]
   _timers: Map<string, number>
   _seqTimers: Array<string>
-  _types: LoggerTypesConf<DefaultLogTypes | T, L>
+  _types: Record<T, Partial<LoggerConfiguration<L>>> & DefaultLoggerTypes<L>
   _stream: WritableStream | WritableStream[]
   _longestLabel: string
   _secrets: Secrets
@@ -165,7 +166,7 @@ class SignaleImpl<T extends string = DefaultLogTypes, L extends string = Default
 
   _getLongestLabel(): string {
     const {_types} = this
-    const labels = Object.keys(_types).map(x => _types[x as T].label)
+    const labels = Object.keys(_types).map(x => _types[x as T].label || '')
     return labels.reduce((x, y) => x.length > y.length ? x : y)
   }
 
@@ -173,8 +174,8 @@ class SignaleImpl<T extends string = DefaultLogTypes, L extends string = Default
     return level && Object.keys(this._logLevels).includes(level) ? level : 'debug'
   }
 
-  _mergeTypes(standard: LoggerTypesConf<DefaultLogTypes>, custom: Partial<LoggerTypesConf<T, L>>): LoggerTypesConf<T | DefaultLogTypes, L> {
-    const types: LoggerTypesConf<T | DefaultLogTypes, L> = Object.assign({}, standard) as LoggerTypesConf<T | DefaultLogTypes, L>
+  _mergeTypes(standard: DefaultLoggerTypes<L>, custom: LoggerTypesConf<T, L>): Record<T, Partial<LoggerConfiguration<L>>> & DefaultLoggerTypes<L> {
+    const types: Record<T, Partial<LoggerConfiguration<L>>> & DefaultLoggerTypes<L> = Object.assign({}, standard) as Record<T, Partial<LoggerConfiguration<L>>> & DefaultLoggerTypes<L>
 
     Object.keys(custom).forEach(type => {
       types[type as T] = Object.assign({}, types[type as T], custom[type as T])
@@ -255,7 +256,7 @@ class SignaleImpl<T extends string = DefaultLogTypes, L extends string = Default
     return (suffix || prefix) ? '' : this._formatMessage(args)
   }
 
-  _buildSignale(type: LoggerConfiguration<L>, ...args: any[]): string {
+  _buildSignale(type: Partial<LoggerConfiguration<L>>, ...args: any[]): string {
     let msg
     let additional: AdditionalFormatObj = {}
 
@@ -468,11 +469,11 @@ class SignaleImpl<T extends string = DefaultLogTypes, L extends string = Default
   }
 }
 
-export type SignaleType<T extends string = DefaultLogTypes, L extends string = DefaultLogLevels> = Record<T, LoggerFunction> &
+export type SignaleType<T extends string = never, L extends string = never> = Record<T, LoggerFunction> &
   Record<DefaultLogTypes, LoggerFunction> & SignaleImpl<T, L> &
-  (new <T extends string = DefaultLogTypes, L extends string = DefaultLogLevels>(options?: ConstructorOptions<T, L>) => SignaleType<T, L>)
+  (new <T extends string = never, L extends string = never>(options?: ConstructorOptions<T, L>) => SignaleType<T, L>)
 
-export type SignaleConstructor<T extends string = DefaultLogTypes, L extends string = DefaultLogLevels> =
+export type SignaleConstructor<T extends string = never, L extends string = never> =
   new (options?: ConstructorOptions<T, L>) => SignaleType<T, L>
 
 export default SignaleImpl as unknown as SignaleType
diff --git a/src/types.ts b/src/types.ts
index 9d8a43f9..53f33748 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -37,7 +37,7 @@ export type DefaultLogLevels = 'info' | 'timer' | 'debug' | 'warn' | 'error'
 // alias for backward-compatibility
 export type LogLevel = DefaultLogLevels
 
-export interface LoggerConfiguration<L extends string = DefaultLogLevels> {
+export interface LoggerConfiguration<L extends string = never> {
   badge: string,
   color: ChalkColor | '',
   label: string,
@@ -45,7 +45,8 @@ export interface LoggerConfiguration<L extends string = DefaultLogLevels> {
   stream?: WritableStream | WritableStream[],
 }
 
-export type LoggerTypesConf<T extends string, L extends string = DefaultLogLevels> = Record<T, LoggerConfiguration<L>>
+export type LoggerTypesConf<T extends string, L extends string = never> = Record<T, Partial<LoggerConfiguration<L>>>
+export type DefaultLoggerTypes<L extends string = never> = Record<DefaultLogTypes, LoggerConfiguration<L>>
 
 export interface InstanceConfiguration {
   displayBadge?: boolean,
@@ -63,15 +64,18 @@ export interface InstanceConfiguration {
 
 export type ScopeFormatter = (scopePath: string[]) => string
 
-export interface ConstructorOptions<T extends string, L extends string = DefaultLogLevels> {
+export interface ConstructorOptions<T extends string = never, L extends string = never> {
   config?: InstanceConfiguration,
   disabled?: boolean,
   interactive?: boolean,
   logLevel?: L | DefaultLogLevels,
-  logLevels?: Record<L, number>,
+  logLevels?: Partial<Record<DefaultLogLevels, number>> & Record<L, number>,
   scope?: string | string[],
   scopeFormatter?: ScopeFormatter,
   secrets?: Secrets,
   stream?: WritableStream | WritableStream[],
-  types?: Partial<LoggerTypesConf<T, L>>,
+  // we can't negate DefaultLogTypes from string
+  // see https://github.com/microsoft/TypeScript/pull/29317 (not merged as for 31 march 2021)
+  // so we can't distinguish logger configuration between default log types and passed one
+  types?: LoggerTypesConf<T, L> & Partial<LoggerTypesConf<DefaultLogTypes, L>>
 }
diff --git a/test-d/custom-log-levels.ts b/test-d/custom-log-levels.ts
index 21a1bae1..def569fa 100644
--- a/test-d/custom-log-levels.ts
+++ b/test-d/custom-log-levels.ts
@@ -8,6 +8,9 @@ const custom = new Signale({
   },
   logLevel: 'sherlock',
   types: {
+    debug: {
+      color: 'grey',
+    },
     sherlock: {
       badge: '🔎',
       color: 'yellow',
diff --git a/yarn.lock b/yarn.lock
index 5d2a7955..f7024c8b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1202,10 +1202,10 @@ typedarray-to-buffer@^3.1.5:
   dependencies:
     is-typedarray "^1.0.0"
 
-typescript@^4.1.3:
-  version "4.1.3"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.1.3.tgz#519d582bd94cba0cf8934c7d8e8467e473f53bb7"
-  integrity sha512-B3ZIOf1IKeH2ixgHhj6la6xdwR9QrLC5d1VKeCSY4tvkqhF2eqd9O7txNlS0PO3GrBAFIdr3L1ndNwteUbZLYg==
+typescript@^4.2.3:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.2.3.tgz#39062d8019912d43726298f09493d598048c1ce3"
+  integrity sha512-qOcYwxaByStAWrBf4x0fibwZvMRG+r4cQoTjbPtUlrWjBHbmCAww1i448U0GJ+3cNNEtebDteo/cHOR3xJ4wEw==
 
 unique-string@^2.0.0:
   version "2.0.0"