diff --git a/source/net/yacy/search/index/MetadataRepository.java b/source/net/yacy/search/index/MetadataRepository.java
index 6bf2f8225..e2e03ad5f 100644
--- a/source/net/yacy/search/index/MetadataRepository.java
+++ b/source/net/yacy/search/index/MetadataRepository.java
@@ -203,6 +203,7 @@ public final class MetadataRepository implements /*Metadata,*/ Iterable<byte[]>
     }
 
     public boolean exists(final byte[] urlHash) {
+        if (urlHash == null) return false;
         try {
             if (this.solr != null && this.solr.exists(ASCII.String(urlHash))) {
                 return true;