diff --git a/Trigger/TrigEvent/TrigNavStructure/TrigNavStructure/TrigNavStructure.h b/Trigger/TrigEvent/TrigNavStructure/TrigNavStructure/TrigNavStructure.h
index 675e07a5fe631393e41ca213f5485b359af79f86..8a508f5582afe389c4a4d3e9d0cda59a5cdca68d 100644
--- a/Trigger/TrigEvent/TrigNavStructure/TrigNavStructure/TrigNavStructure.h
+++ b/Trigger/TrigEvent/TrigNavStructure/TrigNavStructure/TrigNavStructure.h
@@ -1,7 +1,7 @@
 // Dear emacs, this is -*- c++ -*-
 
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 
@@ -187,6 +187,11 @@ namespace HLT {
      */
     std::vector<TriggerElement*>& getAllTEs() { return m_factory.listOfProduced(); } 
 
+    /**
+     * @brief access needed by slimming tools.
+     */
+    const std::vector<TriggerElement*>& getAllTEs() const { return m_factory.listOfProduced(); } 
+
     /**
      * @brief The query returning a collection of all TriggerElements if name is given
      * @param id name of TE, if "" given all TEs are returned