--- dynmap-orig/DynmapCore/src/main/java/org/dynmap/markers/impl/MarkerSignManager.java	2019-06-05 00:35:46.000000000 +0200
+++ dynmap/DynmapCore/src/main/java/org/dynmap/markers/impl/MarkerSignManager.java	2019-06-05 12:26:14.000000000 +0200
@@ -19,9 +19,6 @@
     private static MarkerSignManager mgr = null;
     private static DynmapCore plugin = null;
     private static String defSignSet = null;
-
-    private static final int SIGNPOST_ID = 63;
-    private static final int WALLSIGN_ID = 68;

     private static class SignRec {
         String wname;
@@ -148,12 +145,11 @@
                     iter.remove();
                 }
                 else {
-                    /* Get block ID */
-                    int blkid = plugin.getServer().getBlockIDAt(r.wname, r.x, r.y, r.z);
-                    if((blkid >= 0) && (blkid != WALLSIGN_ID) && (blkid != SIGNPOST_ID)) {
+                    // cokoliv, co NENÍ cedule
+                    if (!plugin.getServer().isSignAt(r.wname, r.x, r.y, r.z)) {
                         r.m.deleteMarker();
                         iter.remove();
-                    }
+                    }
                 }
             }
             plugin.getServer().scheduleServerTask(sl, 60*20);