diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd0e980b..df5ba5db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 ### Fixed
+- Normalize the representation of the "default language" locale (#124)
 
 ### Changed
 
diff --git a/Editor/UI/Localization/Localizer.cs b/Editor/UI/Localization/Localizer.cs
index ea36e265..d92e1b17 100644
--- a/Editor/UI/Localization/Localizer.cs
+++ b/Editor/UI/Localization/Localizer.cs
@@ -40,7 +40,7 @@ public sealed class Localizer
         /// <param name="loader"></param>
         public Localizer(string defaultLanguage, Func<List<(string, Func<string, string>)>> loader)
         {
-            DefaultLanguage = defaultLanguage;
+            DefaultLanguage = CultureInfo.GetCultureInfo(defaultLanguage).Name;
             LanguagePrefs.RegisterLanguage(defaultLanguage);
 
             _localizationLoader = loader;