diff --git a/arangod/Aql/ExecutionEngine.cpp b/arangod/Aql/ExecutionEngine.cpp
index 2f5e05973f..60289ad86c 100644
--- a/arangod/Aql/ExecutionEngine.cpp
+++ b/arangod/Aql/ExecutionEngine.cpp
@@ -357,6 +357,7 @@ struct CoordinatorInstanciator : public WalkerWorker<ExecutionNode> {
           ExecutionNode const* current = (*it).nodes.front();
           ExecutionNode* previous = nullptr;
 
+          // TODO: fix instanciation here as in DBserver case
           while (current != nullptr) {
             auto clone = current->clone(newPlan, false, true);
             newPlan->registerNode(clone);
diff --git a/arangod/Aql/ExecutionEngine.h b/arangod/Aql/ExecutionEngine.h
index 0ec66351d5..1d81793361 100644
--- a/arangod/Aql/ExecutionEngine.h
+++ b/arangod/Aql/ExecutionEngine.h
@@ -132,7 +132,10 @@ namespace triagens {
 ////////////////////////////////////////////////////////////////////////////////
 
         int shutdown () {
-          return _root->shutdown();
+          if (_root != nullptr) {
+            return _root->shutdown();
+          }
+          else return 0;
         }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/Aql/Query.cpp b/arangod/Aql/Query.cpp
index 5f4a8533d1..ccf9747397 100644
--- a/arangod/Aql/Query.cpp
+++ b/arangod/Aql/Query.cpp
@@ -976,6 +976,7 @@ std::string Query::getStateString () const {
 
 void Query::cleanupPlanAndEngine () {
   if (_engine != nullptr) {
+    _engine->shutdown();
     delete _engine;
     _engine = nullptr;
   }