diff --git a/GaudiKernel/include/GaudiKernel/DataHandleHolderBase.h b/GaudiKernel/include/GaudiKernel/DataHandleHolderBase.h
index 821d3d71ea4e5d135359eba409305444adc9ef94..b98ac91a5aff2765f19a18ea8bd7efffe4f7046f 100644
--- a/GaudiKernel/include/GaudiKernel/DataHandleHolderBase.h
+++ b/GaudiKernel/include/GaudiKernel/DataHandleHolderBase.h
@@ -1,5 +1,5 @@
 /***********************************************************************************\
-* (c) Copyright 1998-2019 CERN for the benefit of the LHCb and ATLAS collaborations *
+* (c) Copyright 1998-2022 CERN for the benefit of the LHCb and ATLAS collaborations *
 *                                                                                   *
 * This software is distributed under the terms of the Apache version 2 licence,     *
 * copied verbatim in the file "LICENSE".                                            *
@@ -100,8 +100,10 @@ protected:
 private:
   std::unordered_set<Gaudi::DataHandle*> m_handles;
 
-  Gaudi::Property<DataObjIDColl> m_extInputDataObjs{ this, "ExtraInputs", DataObjIDColl{} };
-  Gaudi::Property<DataObjIDColl> m_extOutputDataObjs{ this, "ExtraOutputs", DataObjIDColl{} };
+  Gaudi::Property<DataObjIDColl> m_extInputDataObjs{ this, "ExtraInputs", DataObjIDColl{},
+                                                     "Additional input dependencies", "OrderedSet<DataObjID>" };
+  Gaudi::Property<DataObjIDColl> m_extOutputDataObjs{ this, "ExtraOutputs", DataObjIDColl{},
+                                                      "Additional output dependencies", "OrderedSet<DataObjID>" };
 };
 
 #endif // !GAUDIKERNEL_DATAHANDLEHOLDERBASE