diff --git a/src/module.ts b/src/module.ts
index 8afed9c..d1c10b1 100644
--- a/src/module.ts
+++ b/src/module.ts
@@ -1,4 +1,5 @@
 import { defineNuxtModule, addPlugin, addImports, createResolver, addTemplate } from '@nuxt/kit'
+import type { BuiltInLocale, BuiltInPluginName } from './types'
 
 export interface RelativeTimeOptions {
   future: string,
@@ -52,12 +53,12 @@ export interface ModuleOptions {
    * @example ['en', 'fr']
    */
 
-  locales?: string[]
+  locales?: BuiltInLocale[]
 
   /**
    * The default locale to use
    */
-  defaultLocale?: string | [string, DefaultLocaleOptions]
+  defaultLocale?: BuiltInLocale | [BuiltInLocale, DefaultLocaleOptions]
 
 
   /**
@@ -70,7 +71,7 @@ export interface ModuleOptions {
    * @example ['timezone', 'utc']
    */
 
-  plugins?: string[]
+  plugins?: BuiltInPluginName[]
 
   /**
    * An array of external optional plugins to load
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..175febb
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,326 @@
+export type BuiltInLocale =
+  | 'af'
+  | 'af'
+  | 'am'
+  | 'am'
+  | 'ar-dz'
+  | 'ar-dz'
+  | 'ar-iq'
+  | 'ar-iq'
+  | 'ar-kw'
+  | 'ar-kw'
+  | 'ar-ly'
+  | 'ar-ly'
+  | 'ar-ma'
+  | 'ar-ma'
+  | 'ar-sa'
+  | 'ar-sa'
+  | 'ar-tn'
+  | 'ar-tn'
+  | 'ar'
+  | 'ar'
+  | 'az'
+  | 'az'
+  | 'be'
+  | 'be'
+  | 'bg'
+  | 'bg'
+  | 'bi'
+  | 'bi'
+  | 'bm'
+  | 'bm'
+  | 'bn-bd'
+  | 'bn-bd'
+  | 'bn'
+  | 'bn'
+  | 'bo'
+  | 'bo'
+  | 'br'
+  | 'br'
+  | 'bs'
+  | 'bs'
+  | 'ca'
+  | 'ca'
+  | 'cs'
+  | 'cs'
+  | 'cv'
+  | 'cv'
+  | 'cy'
+  | 'cy'
+  | 'da'
+  | 'da'
+  | 'de-at'
+  | 'de-at'
+  | 'de-ch'
+  | 'de-ch'
+  | 'de'
+  | 'de'
+  | 'dv'
+  | 'dv'
+  | 'el'
+  | 'el'
+  | 'en-au'
+  | 'en-au'
+  | 'en-ca'
+  | 'en-ca'
+  | 'en-gb'
+  | 'en-gb'
+  | 'en-ie'
+  | 'en-ie'
+  | 'en-il'
+  | 'en-il'
+  | 'en-in'
+  | 'en-in'
+  | 'en-nz'
+  | 'en-nz'
+  | 'en-sg'
+  | 'en-sg'
+  | 'en-tt'
+  | 'en-tt'
+  | 'en'
+  | 'en'
+  | 'eo'
+  | 'eo'
+  | 'es-do'
+  | 'es-do'
+  | 'es-mx'
+  | 'es-mx'
+  | 'es-pr'
+  | 'es-pr'
+  | 'es-us'
+  | 'es-us'
+  | 'es'
+  | 'es'
+  | 'et'
+  | 'et'
+  | 'eu'
+  | 'eu'
+  | 'fa'
+  | 'fa'
+  | 'fi'
+  | 'fi'
+  | 'fo'
+  | 'fo'
+  | 'fr-ca'
+  | 'fr-ca'
+  | 'fr-ch'
+  | 'fr-ch'
+  | 'fr'
+  | 'fr'
+  | 'fy'
+  | 'fy'
+  | 'ga'
+  | 'ga'
+  | 'gd'
+  | 'gd'
+  | 'gl'
+  | 'gl'
+  | 'gom-latn'
+  | 'gom-latn'
+  | 'gu'
+  | 'gu'
+  | 'he'
+  | 'he'
+  | 'hi'
+  | 'hi'
+  | 'hr'
+  | 'hr'
+  | 'ht'
+  | 'ht'
+  | 'hu'
+  | 'hu'
+  | 'hy-am'
+  | 'hy-am'
+  | 'id'
+  | 'id'
+  | 'is'
+  | 'is'
+  | 'it-ch'
+  | 'it-ch'
+  | 'it'
+  | 'it'
+  | 'ja'
+  | 'ja'
+  | 'jv'
+  | 'jv'
+  | 'ka'
+  | 'ka'
+  | 'kk'
+  | 'kk'
+  | 'km'
+  | 'km'
+  | 'kn'
+  | 'kn'
+  | 'ko'
+  | 'ko'
+  | 'ku'
+  | 'ku'
+  | 'ky'
+  | 'ky'
+  | 'lb'
+  | 'lb'
+  | 'lo'
+  | 'lo'
+  | 'lt'
+  | 'lt'
+  | 'lv'
+  | 'lv'
+  | 'me'
+  | 'me'
+  | 'mi'
+  | 'mi'
+  | 'mk'
+  | 'mk'
+  | 'ml'
+  | 'ml'
+  | 'mn'
+  | 'mn'
+  | 'mr'
+  | 'mr'
+  | 'ms-my'
+  | 'ms-my'
+  | 'ms'
+  | 'ms'
+  | 'mt'
+  | 'mt'
+  | 'my'
+  | 'my'
+  | 'nb'
+  | 'nb'
+  | 'ne'
+  | 'ne'
+  | 'nl-be'
+  | 'nl-be'
+  | 'nl'
+  | 'nl'
+  | 'nn'
+  | 'nn'
+  | 'oc-lnc'
+  | 'oc-lnc'
+  | 'pa-in'
+  | 'pa-in'
+  | 'pl'
+  | 'pl'
+  | 'pt-br'
+  | 'pt-br'
+  | 'pt'
+  | 'pt'
+  | 'rn'
+  | 'rn'
+  | 'ro'
+  | 'ro'
+  | 'ru'
+  | 'ru'
+  | 'rw'
+  | 'rw'
+  | 'sd'
+  | 'sd'
+  | 'se'
+  | 'se'
+  | 'si'
+  | 'si'
+  | 'sk'
+  | 'sk'
+  | 'sl'
+  | 'sl'
+  | 'sq'
+  | 'sq'
+  | 'sr-cyrl'
+  | 'sr-cyrl'
+  | 'sr'
+  | 'sr'
+  | 'ss'
+  | 'ss'
+  | 'sv-fi'
+  | 'sv-fi'
+  | 'sv'
+  | 'sv'
+  | 'sw'
+  | 'sw'
+  | 'ta'
+  | 'ta'
+  | 'te'
+  | 'te'
+  | 'tet'
+  | 'tet'
+  | 'tg'
+  | 'tg'
+  | 'th'
+  | 'th'
+  | 'tk'
+  | 'tk'
+  | 'tl-ph'
+  | 'tl-ph'
+  | 'tlh'
+  | 'tlh'
+  | 'tr'
+  | 'tr'
+  | 'tzl'
+  | 'tzl'
+  | 'tzm-latn'
+  | 'tzm-latn'
+  | 'tzm'
+  | 'tzm'
+  | 'ug-cn'
+  | 'ug-cn'
+  | 'uk'
+  | 'uk'
+  | 'ur'
+  | 'ur'
+  | 'uz-latn'
+  | 'uz-latn'
+  | 'uz'
+  | 'uz'
+  | 'vi'
+  | 'vi'
+  | 'x-pseudo'
+  | 'x-pseudo'
+  | 'yo'
+  | 'yo'
+  | 'zh-cn'
+  | 'zh-cn'
+  | 'zh-hk'
+  | 'zh-hk'
+  | 'zh-tw'
+  | 'zh-tw'
+  | 'zh'
+  | 'zh'
+
+
+export type BuiltInPluginName =
+  | 'advancedFormat'
+  | 'arraySupport'
+  | 'badMutable'
+  | 'bigIntSupport'
+  | 'buddhistEra'
+  | 'calendar'
+  | 'customParseFormat'
+  | 'dayOfYear'
+  | 'devHelper'
+  | 'duration'
+  | 'isBetween'
+  | 'isLeapYear'
+  | 'isMoment'
+  | 'isSameOrAfter'
+  | 'isSameOrBefore'
+  | 'isToday'
+  | 'isTomorrow'
+  | 'isYesterday'
+  | 'isoWeek'
+  | 'isoWeeksInYear'
+  | 'localeData'
+  | 'localizedFormat'
+  | 'minMax'
+  | 'objectSupport'
+  | 'pluralGetSet'
+  | 'preParsePostFormat'
+  | 'quarterOfYear'
+  | 'relativeTime'
+  | 'timezone'
+  | 'toArray'
+  | 'toObject'
+  | 'updateLocale'
+  | 'utc'
+  | 'weekOfYear'
+  | 'weekYear'
+  | 'weekday'