diff --git a/core/modules/language/config/install/language.mappings.yml b/core/modules/language/config/install/language.mappings.yml
index c2022f1..f7fc321 100644
--- a/core/modules/language/config/install/language.mappings.yml
+++ b/core/modules/language/config/install/language.mappings.yml
@@ -6,5 +6,7 @@ zh: 'zh-hans' # Default Chinese to simplified script
 zh-tw: 'zh-hant' # Taiwan Chinese in traditional script
 zh-hk: 'zh-hant' # Hong Kong Chinese in traditional script
 zh-mo: 'zh-hant' # Macao Chinese in traditional script
+zh-cht: 'zh-hant' # traditional Chinese
 zh-cn: 'zh-hans' # PRC Mainland Chinese in simplified script
 zh-sg: 'zh-hans' # Singapore Chinese in simplified script
+zh-chs: 'zh-hans' # simplified Chinese
diff --git a/core/modules/language/src/Tests/LanguageBrowserDetectionUnitTest.php b/core/modules/language/src/Tests/LanguageBrowserDetectionUnitTest.php
index 3fbcc79..62ee8e3 100644
--- a/core/modules/language/src/Tests/LanguageBrowserDetectionUnitTest.php
+++ b/core/modules/language/src/Tests/LanguageBrowserDetectionUnitTest.php
@@ -145,6 +145,8 @@ function testLanguageFromBrowser() {
       'zh-mo' => 'zh-hant',
       'zh-hans' => 'zh-hans',
       'zh-hant' => 'zh-hant',
+      'zh-chs' => 'zh-hans',
+      'zh-cht' => 'zh-hant',
     );
 
     $mappings = $this->container->get('config.factory')->get('language.mappings')->get();