diff --git a/src/NCollection/NCollection_BaseMap.hxx b/src/NCollection/NCollection_BaseMap.hxx
index 41eac66863..ff6d5c81f7 100644
--- a/src/NCollection/NCollection_BaseMap.hxx
+++ b/src/NCollection/NCollection_BaseMap.hxx
@@ -245,6 +245,8 @@ public:
   NCollection_ListNode ** myData1;
   NCollection_ListNode ** myData2;
 
+  void resetSize() { mySize = 0; }
+
  private: 
   // ---------- PRIVATE FIELDS ------------
   Standard_Integer myNbBuckets;
diff --git a/src/NCollection/NCollection_Map.hxx b/src/NCollection/NCollection_Map.hxx
index 1dd40bd46c..ac16df31fe 100644
--- a/src/NCollection/NCollection_Map.hxx
+++ b/src/NCollection/NCollection_Map.hxx
@@ -378,7 +378,7 @@ public:
   //! Clear data. If doReleaseMemory is false then the table of
   //! buckets is not released and will be reused.
   void Clear(const Standard_Boolean doReleaseMemory = Standard_False)
-  { Destroy (MapNode::delNode, doReleaseMemory); myFirst = myLast = nullptr; }
+  { Destroy (MapNode::delNode, doReleaseMemory); }
 
   //! Clear data and reset allocator
   void Clear (const Handle(NCollection_BaseAllocator)& theAllocator)
@@ -388,6 +388,29 @@ public:
                     NCollection_BaseAllocator::CommonBaseAllocator() );
   }
 
+  //! Deallocate all node elements
+  void Destroy(NCollection_DelMapNode fDel, Standard_Boolean doReleaseMemory)
+  {
+    if (!IsEmpty()) 
+    {
+      MapNode* aNode = myFirst;
+      while (aNode)
+      {
+        MapNode* aCurNode = aNode;
+        aNode = aNode->NextSeq();
+        fDel (aCurNode, myAllocator);
+      }
+      myFirst = myLast = nullptr;
+      memset(myData1, 0, (NbBuckets() + 1) * sizeof(NCollection_ListNode*));
+      resetSize();
+    }
+    if (doReleaseMemory)
+    {
+      Standard::Free(myData1);
+      myData1 = myData2 = nullptr;
+    }
+  }
+
   //! Destructor
   virtual ~NCollection_Map (void)
   { Clear(true); }