diff --git a/src/NCollection/NCollection_IndexedMap.hxx b/src/NCollection/NCollection_IndexedMap.hxx
index f9a150c06e..5a347fe7ea 100644
--- a/src/NCollection/NCollection_IndexedMap.hxx
+++ b/src/NCollection/NCollection_IndexedMap.hxx
@@ -44,7 +44,7 @@ public:
   //! STL-compliant typedef for key type
   typedef TheKeyType key_type;
 
- private:
+ protected:
    // **************** Adaptation of the TListNode to the INDEXEDmap
    class IndexedMapNode : public NCollection_TListNode<TheKeyType>
   {