Index: trunk/src/org/openstreetmap/josm/tools/LanguageInfo.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/LanguageInfo.java	(revision 14641)
+++ trunk/src/org/openstreetmap/josm/tools/LanguageInfo.java	(revision 14642)
@@ -41,8 +41,12 @@
      */
     public static String getWikiLanguagePrefix(LocaleType type) {
+        return getWikiLanguagePrefix(Locale.getDefault(), type);
+    }
+
+    static String getWikiLanguagePrefix(Locale locale, LocaleType type) {
         if (type == LocaleType.ENGLISH)
           return "";
 
-        String code = getJOSMLocaleCode();
+        String code = getJOSMLocaleCode(locale);
         if (type == LocaleType.BASELANGUAGE) {
             if (code.matches("[^_]+_[^_]+")) {