diff --git a/build/jquery.localize.js b/build/jquery.localize.js
index 439c6e2..57f4f25 100644
--- a/build/jquery.localize.js
+++ b/build/jquery.localize.js
@@ -1,12 +1,13 @@
-// Generated by CoffeeScript 1.3.3
+// Generated by CoffeeScript 1.6.3
 (function() {
   var $, normaliseLang;
 
   $ = jQuery;
 
   normaliseLang = function(lang) {
-    lang = lang.replace(/_/, '-').toLowerCase();
-    if (lang.length > 3) {
+    lang = lang.replace(/_/, '-');
+    lang = lang.substring(0, 2).toLowerCase() + lang.substring(2);
+    if (lang.length === 5) {
       lang = lang.substring(0, 3) + lang.substring(3).toUpperCase();
     }
     return lang;
@@ -45,7 +46,7 @@
           break;
         case 3:
           if (lang.length >= 5) {
-            file = "" + pkg + "-" + (lang.substring(0, 5)) + "." + fileExtension;
+            file = "" + pkg + "-" + lang + "." + fileExtension;
             return jsonCall(file, pkg, lang, level);
           }
       }
diff --git a/src/jquery.localize.coffee b/src/jquery.localize.coffee
index 7eb5cdf..b101653 100644
--- a/src/jquery.localize.coffee
+++ b/src/jquery.localize.coffee
@@ -7,10 +7,12 @@
 
 $ = jQuery
 
-# Ensures language code is in the format aa-AA.
+# Ensures language code is in the format aa-AA, or if longer,
+# keep capitalization (zh-Hans) of second part.
 normaliseLang = (lang) ->
-  lang = lang.replace(/_/, '-').toLowerCase()
-  if lang.length > 3
+  lang = lang.replace(/_/, '-')
+  lang = lang.substring(0, 2).toLowerCase() + lang.substring(2)
+  if lang.length == 5
     lang = lang.substring(0, 3) + lang.substring(3).toUpperCase()
   lang
 
@@ -37,7 +39,7 @@ $.localize = (pkg, options = {}) ->
           jsonCall(file, pkg, lang, level)
       when 3
         if lang.length >= 5
-          file = "#{pkg}-#{lang.substring(0, 5)}.#{fileExtension}"
+          file = "#{pkg}-#{lang}.#{fileExtension}"
           jsonCall(file, pkg, lang, level)
 
   jsonCall = (file, pkg, lang, level) ->