diff --git src/org/openstreetmap/gui/jmapviewer/tilesources/AbstractTMSTileSource.java src/org/openstreetmap/gui/jmapviewer/tilesources/AbstractTMSTileSource.java
index 027b550..6b45332 100644
--- src/org/openstreetmap/gui/jmapviewer/tilesources/AbstractTMSTileSource.java
+++ src/org/openstreetmap/gui/jmapviewer/tilesources/AbstractTMSTileSource.java
@@ -133,11 +133,15 @@ public abstract class AbstractTMSTileSource extends AbstractTileSource {
         if(noTileHeaders != null) {
             for (Entry<String, String> searchEntry: noTileHeaders.entrySet()) {
                 List<String> headerVals = headers.get(searchEntry.getKey());
-                if (headerVals != null && headerVals.contains(searchEntry.getValue())) {
+                if (headerVals != null) {
+                    for (String headerValue: headerVals) {
+                        if (headerValue.matches(searchEntry.getValue())) {
                             return true;
                         }
                     }
                 }
+            }
+        }
         return super.isNoTileAtZoom(headers, statusCode, content);
     }
 }