Index: applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaApp.java
===================================================================
--- applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaApp.java	(revision 33287)
+++ applications/editors/josm/plugins/wikipedia/src/org/wikipedia/WikipediaApp.java	(revision 33288)
@@ -46,7 +46,20 @@
     private static final XPath X_PATH = XPath.getInstance();
     private final String wikipediaLang;
+    private final String siteId;
 
     private WikipediaApp(final String wikipediaLang) {
+
+        // FIXME: the proper way to get any wiki's site id is through an API call:
+        // https://zh-yue.wikipedia.org/w/api.php?action=query&meta=siteinfo&siprop=general
+        // use "wikiid" value. The value may be cached as it will never change
+        String siteId = wikipediaLang.replace('-', '_');
+        switch (siteId) {
+            case "be_tarask":
+                siteId = "be_x_old";
+                break;
+        }
+
         this.wikipediaLang = wikipediaLang;
+        this.siteId = siteId + "wiki";
     }
 
@@ -263,6 +276,6 @@
                     "?action=wbgetentities" +
                     "&props=sitelinks" +
-                    "&sites=" + wikipediaLang + "wiki" +
-                    "&sitefilter=" + wikipediaLang + "wiki" +
+                    "&sites=" + siteId +
+                    "&sitefilter=" + siteId +
                     "&format=xml" +
                     "&titles=" + articles.stream().map(Utils::encodeUrl).collect(Collectors.joining("|"));