Index: applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaToggleDialog.java
===================================================================
--- applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaToggleDialog.java	(revision 28224)
+++ applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaToggleDialog.java	(revision 28244)
@@ -48,5 +48,5 @@
                 new SideButton(new WikipediaSettingsAction(), false)));
     }
-    final StringProperty wikipediaLang = new StringProperty("wikipedia.lang", LanguageInfo.getWikiLanguagePrefix());
+    final StringProperty wikipediaLang = new StringProperty("wikipedia.lang", LanguageInfo.getJOSMLocaleCode().substring(0, 2));
     final DefaultListModel<WikipediaEntry> model = new DefaultListModel<WikipediaEntry>();
     final JList<WikipediaEntry> list = new JList<WikipediaEntry>(model) {
@@ -116,5 +116,5 @@
                 return null;
             }
-            return new Tag("wikipedia:" + m.group(1), m.group(2));
+            return new Tag("wikipedia", m.group(1) + ":" + m.group(2));
         }