diff --git a/src/NCollection/NCollection_BaseVector.cxx b/src/NCollection/NCollection_BaseVector.cxx
index f830bbbc58..633ba1e48d 100755
--- a/src/NCollection/NCollection_BaseVector.cxx
+++ b/src/NCollection/NCollection_BaseVector.cxx
@@ -125,7 +125,7 @@ void * NCollection_BaseVector::ExpandV (const Standard_Integer theIndex)
     MemBlock& aLastBlock = myData [myNBlocks - 1];
     Standard_RangeError_Raise_if (theIndex < aLastBlock.FirstIndex(),
                                   "NColelction_BaseVector::ExpandV");
-    const unsigned int anIndLastBlock = theIndex - aLastBlock.FirstIndex();
+    Standard_Integer anIndLastBlock = theIndex - aLastBlock.FirstIndex();
     //  Is there still room for 1 item in the last array?
     if (anIndLastBlock < aLastBlock.Size()) {
       myLength = aNewLength;
diff --git a/src/NCollection/NCollection_BaseVector.hxx b/src/NCollection/NCollection_BaseVector.hxx
index bf1d1473fe..f57cac7068 100755
--- a/src/NCollection/NCollection_BaseVector.hxx
+++ b/src/NCollection/NCollection_BaseVector.hxx
@@ -45,14 +45,14 @@ class NCollection_BaseVector
       : myAlloc(theAlloc),
         myFirstInd(theFirstInd), myLength(0), mySize(theLength), myData(0L) {}
     virtual void        Reinit     (const Standard_Integer,
-                                    const size_t) {}
+                                    const Standard_Integer) {}
     Standard_Integer    FirstIndex () const     { return myFirstInd; }
-    size_t              Size       () const     { return mySize; }
+    Standard_Integer    Size       () const     { return mySize; }
   public:
     virtual             ~MemBlock () {}
-    void                SetLength  (const size_t theLen)
+    void                SetLength  (const Standard_Integer theLen)
                                                 { myLength = theLen; }
-    size_t              Length     () const     { return myLength; }
+    Standard_Integer    Length     () const     { return myLength; }
     void *              Find       (const Standard_Integer theInd,
                                     const size_t           theSize) const
                                     { return ((char *) myData)+theInd*theSize;}
@@ -60,8 +60,8 @@ class NCollection_BaseVector
                         GetIndexV  (void * theItem, const size_t theSz) const;
   protected:
     Standard_Integer             myFirstInd;
-    size_t                       myLength;
-    size_t                       mySize;
+    Standard_Integer             myLength;
+    Standard_Integer             mySize;
     NCollection_BaseAllocator    * myAlloc;
     void                         * myData;
     friend class NCollection_BaseVector;
@@ -85,10 +85,10 @@ class NCollection_BaseVector
         { return &myVector -> myData[myICurBlock]; }
 
     const NCollection_BaseVector * myVector;   // the Master vector
-    size_t                       myICurBlock;  // # of the current block
-    size_t                       myIEndBlock;
-    size_t                       myCurIndex;   // Index in the current block
-    size_t                       myEndIndex;
+    Standard_Integer             myICurBlock;  // # of the current block
+    Standard_Integer             myIEndBlock;
+    Standard_Integer             myCurIndex;   // Index in the current block
+    Standard_Integer             myEndIndex;
   };
 
  protected:
diff --git a/src/NCollection/NCollection_Vector.hxx b/src/NCollection/NCollection_Vector.hxx
index fa687d308d..d18f669ab6 100755
--- a/src/NCollection/NCollection_Vector.hxx
+++ b/src/NCollection/NCollection_Vector.hxx
@@ -67,7 +67,7 @@ template <class TheItemType> class NCollection_Vector
       : NCollection_BaseVector::MemBlock (theFirstInd, theSize, theAlloc)
     {
       myData = myAlloc->Allocate(theSize * sizeof(TheItemType));
-      for (size_t i=0; i < theSize; i++)
+      for (Standard_Integer i=0; i < theSize; i++)
         new (&((TheItemType *) myData)[i]) TheItemType;
     }
     //! Copy constructor
@@ -77,7 +77,7 @@ template <class TheItemType> class NCollection_Vector
     {
       myLength = theOther.Length();
       myData = myAlloc->Allocate(Size() * sizeof(TheItemType));
-      size_t i;
+      Standard_Integer i;
       for (i=0; i < Length(); i++)
         new (&((TheItemType *) myData)[i]) TheItemType(theOther.Value(i));
       for (; i < Size(); i++)
@@ -85,17 +85,17 @@ template <class TheItemType> class NCollection_Vector
     }
     //! Reinit
     virtual void Reinit (const Standard_Integer theFirst,
-                         const size_t           theSize)
+                         const Standard_Integer theSize)
     {
       if (myData) {
-        for (size_t i=0; i < mySize; i++)
+        for (Standard_Integer i=0; i < mySize; i++)
           ((TheItemType *) myData)[i].~TheItemTypeD();
         myAlloc->Free(myData);
         myData = NULL;
       }
       if (theSize > 0) {
         myData = myAlloc->Allocate(theSize * sizeof(TheItemType));
-        for (size_t i=0; i < theSize; i++)
+        for (Standard_Integer i=0; i < theSize; i++)
           new (&((TheItemType *) myData)[i]) TheItemType;
       }
       myFirstInd = theFirst;
@@ -106,7 +106,7 @@ template <class TheItemType> class NCollection_Vector
     virtual ~MemBlock ()
     {
       if (myData) {
-        for (size_t i=0; i < Size(); i++)
+        for (Standard_Integer i=0; i < Size(); i++)
           ((TheItemType *) myData)[i].~TheItemTypeD();
         myAlloc->Free(myData);
         myData = NULL;