diff --git a/vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java b/vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java
index 59e9bb594..b181d3557 100644
--- a/vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java
+++ b/vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java
@@ -137,7 +137,8 @@ public void completed(QueryResult result) {
         mTileLayer.callHooksComplete(mTile, ok);
 
         /* finish buckets- tessellate and cleanup on worker-thread */
-        mBuckets.prepare();
+        if (mBuckets != null)
+            mBuckets.prepare();
         clearState();
 
         super.completed(result);