diff --git a/tests/data/index.ts b/tests/data/index.ts
index 9fb48b3..05e079d 100644
--- a/tests/data/index.ts
+++ b/tests/data/index.ts
@@ -26,8 +26,8 @@ export const CONFIG:Config<
     },
     {
       key: 'common',
-      locale: 'cs',
-      loader: async () => (import('../data/translations/cs/common.json')),
+      locale: 'zh-Hans',
+      loader: async () => (import('../data/translations/zh-Hans/common.json')),
     },
   ],
   parserOptions: {
diff --git a/tests/data/translations/index.ts b/tests/data/translations/index.ts
index c2d1fae..f1b371a 100644
--- a/tests/data/translations/index.ts
+++ b/tests/data/translations/index.ts
@@ -1,7 +1,9 @@
+import { toDotNotation } from '../../utils';
+
 import * as common from './en/common.json';
 import * as route from './en/route.json';
-import * as common_cs from './cs/common.json';
-import { toDotNotation } from '../../utils';
+import * as common_ku from './ku/common.json';
+import * as common_zhHans from './zh-Hans/common.json';
 
 export default ({
   en: toDotNotation({
@@ -9,7 +11,10 @@ export default ({
     route1: route,
     route2: route,
   }),
-  cs: toDotNotation({
-    common: common_cs,
+  'zh-Hans': toDotNotation({
+    common: common_zhHans,
+  }),
+  ku: toDotNotation({
+    common: common_ku,
   }),
 }) as Record<string, any>;
\ No newline at end of file
diff --git a/tests/data/translations/cs/common.json b/tests/data/translations/ku/common.json
similarity index 100%
rename from tests/data/translations/cs/common.json
rename to tests/data/translations/ku/common.json
diff --git a/tests/data/translations/zh-Hans/common.json b/tests/data/translations/zh-Hans/common.json
new file mode 100644
index 0000000..3cf6df0
--- /dev/null
+++ b/tests/data/translations/zh-Hans/common.json
@@ -0,0 +1,9 @@
+{
+  "no_placeholder": "NO_PLACEHOLDER",
+  "placeholder": "VALUES: {{value}}, {{value;}}, {{ value }}, {{ value; }}",
+  "modifier_test": "VALUES: {{value; option1:VALUE1; option2:VALUE2; default:DEFAULT VALUE;}}, {{ value ; option1 : VALUE1 ; option2 : VALUE2 ; default : DEFAULT VALUE ;}}",
+  "custom_modifier": "{{date:date;}}",
+  "modifier_number": "{{value:number;}}",
+  "modifier_date": "{{value:date;}}",
+  "modifier_ago": "{{value:ago;}}"
+}
\ No newline at end of file
diff --git a/tests/specs/index.spec.ts b/tests/specs/index.spec.ts
index ca6ab30..e19412f 100644
--- a/tests/specs/index.spec.ts
+++ b/tests/specs/index.spec.ts
@@ -3,7 +3,7 @@ import i18n from '../../src';
 import { CONFIG, TRANSLATIONS } from '../data';
 import { filterTranslationKeys } from '../utils';
 
-const { initLocale = '', loaders } = CONFIG;
+const { initLocale = '', loaders = [] } = CONFIG;
 
 describe('i18n instance', () => {
   it('exports all properties and methods', () => {
@@ -27,7 +27,7 @@ describe('i18n instance', () => {
 
     setRoute('/');
     const $initialized = get(initialized);
-    const $loading = get(loading);
+    const $loading = loading.get();
     const $locale = locale.get();
 
     expect($locale).toBe(undefined);
@@ -39,7 +39,7 @@ describe('i18n instance', () => {
 
     await setLocale(initLocale);
     setRoute('/');
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(true);
 
     const $initialized = get(initialized);
@@ -50,7 +50,7 @@ describe('i18n instance', () => {
 
     setLocale(initLocale);
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(false);
   });
   it('`setLocale` method triggers loading when route is set', async () => {
@@ -59,7 +59,7 @@ describe('i18n instance', () => {
     await setRoute('');
     setLocale(initLocale);
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(true);
   });
   it('`setLocale` does not set `unknown` locale', async () => {
@@ -67,7 +67,7 @@ describe('i18n instance', () => {
 
     setLocale('unknown');
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     const $locale = locale.get();
 
     expect($loading).toBe(false);
@@ -78,7 +78,7 @@ describe('i18n instance', () => {
 
     locale.set(initLocale);
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(false);
 
     await loading.toPromise();
@@ -92,7 +92,7 @@ describe('i18n instance', () => {
     await setRoute('');
     locale.set(initLocale);
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(true);
 
     await loading.toPromise();
@@ -106,7 +106,7 @@ describe('i18n instance', () => {
     await setRoute('');
     locale.set(initLocale.toUpperCase());
 
-    const $loading = get(loading);
+    const $loading = loading.get();
     expect($loading).toBe(true);
 
     await loading.toPromise();
@@ -117,13 +117,38 @@ describe('i18n instance', () => {
     const $locale = locale.get();
     expect($locale).toBe(initLocale.toLocaleLowerCase());
   });
+  it('`locale` can be non-standard', async () => {
+    const nonStandardLocale = 'ku';
+    const { loading, locale, locales, setRoute, initialized, translations } = new i18n({ loaders: [{ key: 'common', locale: `${nonStandardLocale}`.toUpperCase(), loader: () => import(`../data/translations/${nonStandardLocale}/common.json`) }] });
+    await setRoute('');
+    locale.set(nonStandardLocale);
+
+    const $loading = loading.get();
+    expect($loading).toBe(true);
+
+    await loading.toPromise();
+
+    const $initialized = get(initialized);
+    expect($initialized).toBe(true);
+
+    const $locale = locale.get();
+    expect($locale).toBe(nonStandardLocale);
+
+    const $locales = locales.get();
+    expect($locales).toContainEqual(nonStandardLocale);
+
+    const $translations = translations.get();
+    expect($translations[nonStandardLocale]).toEqual(
+      expect.objectContaining(filterTranslationKeys(TRANSLATIONS[nonStandardLocale], ['common'])),
+    );
+  });
   it('`getTranslationProps` method works', async () => {
     const { initialized, getTranslationProps } = new i18n({ loaders });
 
     const [translations = {}] = await getTranslationProps(initLocale);
     const $initialized = get(initialized);
 
-    const keys = (loaders || []).filter(({ routes }) => !routes).map(({ key }) => key);
+    const keys = loaders.filter(({ routes }) => !routes).map(({ key }) => key);
 
     expect(translations[initLocale]).toEqual(
       expect.objectContaining(filterTranslationKeys(TRANSLATIONS[initLocale], keys)),
@@ -147,7 +172,7 @@ describe('i18n instance', () => {
     addTranslations(TRANSLATIONS);
     loadTranslations(initLocale);
 
-    expect(get(loading)).toBe(false);
+    expect(loading.get()).toBe(false);
   });
   it('initializes properly with `initLocale`', async () => {
     const { initialized, loadConfig } = new i18n();
@@ -175,7 +200,7 @@ describe('i18n instance', () => {
       outputArray.push($loading);
     });
 
-    await loadConfig(CONFIG).then(() => expect(get(loading)).toBe(false));
+    await loadConfig(CONFIG).then(() => expect(loading.get()).toBe(false));
 
     testArray.forEach((value, index) => {
       expect(value).toBe(testArray[index]);
@@ -214,7 +239,7 @@ describe('i18n instance', () => {
   });
   it('includes both `translations` when using `fallbackLocale`', async () => {
     const { translations, locales, loadConfig } = new i18n();
-    const fallbackLocale = CONFIG.loaders?.find(({ locale }) => locale.toLowerCase() !== CONFIG.initLocale?.toLowerCase())?.locale;
+    const fallbackLocale = loaders.find(({ locale }) => locale.toLowerCase() !== initLocale?.toLowerCase())?.locale;
 
     await loadConfig({ ...CONFIG, fallbackLocale });
     const $translations = translations.get();