Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/MapCSSTagChecker.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/MapCSSTagChecker.java	(revision 7712)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/MapCSSTagChecker.java	(revision 7713)
@@ -574,5 +574,6 @@
         CheckParameterUtil.ensureParameterNotNull(url, "url");
         CachedFile cache = new CachedFile(url);
-        try (InputStream s = cache.getInputStream()) {
+        InputStream zip = cache.findZipEntryInputStream("validator.mapcss", "");
+        try (InputStream s = zip != null ? zip : cache.getInputStream()) {
             List<TagCheck> tagchecks = TagCheck.readMapCSS(new BufferedReader(UTFInputStreamReader.create(s)));
             checks.remove(url);