diff --git a/arangod/Aql/ExecutionBlock.cpp b/arangod/Aql/ExecutionBlock.cpp
index 441678f57f..baea4a4379 100644
--- a/arangod/Aql/ExecutionBlock.cpp
+++ b/arangod/Aql/ExecutionBlock.cpp
@@ -3638,6 +3638,36 @@ bool ScatterBlock::hasMore () {
   return false;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief remainingForShard: remaining for shard, sum of the number of row left
+/// in the buffer and _dependencies[0]->remaining()
+////////////////////////////////////////////////////////////////////////////////
+
+int64_t ScatterBlock::remainingForShard (std::string const& shardId) {
+  
+  size_t clientId = getClientId(shardId);
+
+  if (_doneForClient.at(clientId)) {
+    return 0;
+  }
+  
+  int64_t sum = _dependencies[0]->remaining();
+  if (sum == -1) {
+    return -1;
+  }
+
+  std::pair<size_t,size_t> pos = _posForClient.at(clientId);
+
+  if (pos.first <= _buffer.size()) {
+    sum += _buffer.at(pos.first)->size() - pos.second;
+    for (auto i = pos.first + 1; i < _buffer.size(); i++) {
+      sum += _buffer.at(i)->size();
+    }
+  }
+
+  return sum;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief hasMoreForShard: any more for shard <shardId>?
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/Aql/ExecutionBlock.h b/arangod/Aql/ExecutionBlock.h
index db4ebe03f0..90b3311566 100644
--- a/arangod/Aql/ExecutionBlock.h
+++ b/arangod/Aql/ExecutionBlock.h
@@ -1574,7 +1574,7 @@ namespace triagens {
 ////////////////////////////////////////////////////////////////////////////////
 
         int64_t remaining () {
-          return _dependencies[0]->remaining();
+          TRI_ASSERT(false);
         }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1606,6 +1606,12 @@ namespace triagens {
 ////////////////////////////////////////////////////////////////////////////////
         
         bool hasMoreForShard (std::string const& shardId);
+       
+////////////////////////////////////////////////////////////////////////////////
+/// @brief remainingForShard: remaining for shard <shardId>?
+////////////////////////////////////////////////////////////////////////////////
+        
+        int64_t remainingForShard (std::string const& shardId);
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief getOrSkipSomeForShard