diff --git a/Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeLocale.cpp b/Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeLocale.cpp
index 7a2e22f1a4b..7ea7c2e3f1e 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeLocale.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeLocale.cpp
@@ -464,6 +464,39 @@ static void parse_numeric_keywords(String locale_numbers_path, UnicodeLocaleData
         locale_data.keywords.append(key);
 }
 
+static void parse_default_content_locales(String core_path, UnicodeLocaleData& locale_data)
+{
+    LexicalPath default_content_path(move(core_path));
+    default_content_path = default_content_path.append("defaultContent.json"sv);
+    VERIFY(Core::File::exists(default_content_path.string()));
+
+    auto default_content_file_or_error = Core::File::open(default_content_path.string(), Core::OpenMode::ReadOnly);
+    VERIFY(!default_content_file_or_error.is_error());
+
+    auto default_content = JsonParser(default_content_file_or_error.value()->read_all()).parse();
+    VERIFY(default_content.has_value());
+
+    auto const& default_content_array = default_content->as_object().get("defaultContent"sv);
+
+    default_content_array.as_array().for_each([&](JsonValue const& value) {
+        auto locale = value.as_string();
+        StringView default_locale = locale;
+
+        while (true) {
+            if (locale_data.locales.contains(default_locale))
+                break;
+
+            auto pos = default_locale.find_last('-');
+            if (!pos.has_value())
+                return;
+
+            default_locale = default_locale.substring_view(0, *pos);
+        }
+
+        locale_data.locales.set(locale, locale_data.locales.get(default_locale).value());
+    });
+}
+
 static Core::DirIterator path_to_dir_iterator(String path)
 {
     LexicalPath lexical_path(move(path));
@@ -486,7 +519,7 @@ static void parse_all_locales(String core_path, String locale_names_path, String
     auto misc_iterator = path_to_dir_iterator(move(misc_path));
     auto numbers_iterator = path_to_dir_iterator(move(numbers_path));
 
-    LexicalPath core_supplemental_path(move(core_path));
+    LexicalPath core_supplemental_path(core_path);
     core_supplemental_path = core_supplemental_path.append("supplemental"sv);
     VERIFY(Core::File::is_directory(core_supplemental_path.string()));
 
@@ -558,6 +591,8 @@ static void parse_all_locales(String core_path, String locale_names_path, String
         parse_locale_currencies(numbers_path, locale_data, locale);
         parse_numeric_keywords(numbers_path, locale_data, locale);
     }
+
+    parse_default_content_locales(move(core_path), locale_data);
 }
 
 static String format_identifier(StringView owner, String identifier)
diff --git a/Tests/LibUnicode/TestUnicodeLocale.cpp b/Tests/LibUnicode/TestUnicodeLocale.cpp
index a82b9eae2b8..34619c8cd78 100644
--- a/Tests/LibUnicode/TestUnicodeLocale.cpp
+++ b/Tests/LibUnicode/TestUnicodeLocale.cpp
@@ -456,4 +456,10 @@ TEST_CASE(canonicalize_unicode_locale_id)
     test("ZH-XIANG"sv, "hsn"sv);
     test("ja-latn-hepburn-heploc"sv, "ja-Latn-alalc97"sv);
     test("JA-LATN-HEPBURN-HEPLOC"sv, "ja-Latn-alalc97"sv);
+
+    // Default content.
+    test("en-us"sv, "en-US"sv);
+    test("EN-US"sv, "en-US"sv);
+    test("zh-Hans-CN"sv, "zh-Hans-CN"sv);
+    test("ZH-HANS-CN"sv, "zh-Hans-CN"sv);
 }