diff --git a/ChangeLog.txt b/ChangeLog.txt
index eb4b78ae50..93213a791a 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -10,6 +10,21 @@
      * Change, ! Fix, % Optimization, + Addition, - Removal, ; Comment
  */
 
+2017-05-10 17:21 UTC+0200 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * contrib/hbwin/olecore.c
+    + added functions which changes default method of NIL conversion to
+      OLE variant:
+         __oleVariantNil2Null( [<lNewNil2NullFlag>] ) -> <lPrevNil2NullFlag>
+      By default NIL values passed to foreign OLE code are converted to
+      VT_EMPTY variants. __oleVariantNil2Null( .t. ) changes this behavior
+      so NIL values are converted to VT_NULL variants.
+    ; Warning: This function was added for tests. Looks that it's expected
+               behavior for communication with MS-Excel and allows to use
+               NIL as default parameter value but potentially it may create
+               problems with some custom OLE interfaces so this modification
+               should be widely tested in real life before we change the
+               default behavior.
+
 2017-05-10 16:39 UTC+0200 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
   * contrib/hbwin/olecore.c
     - removed support for VT_DECIMAL and VT_PTR arrays from
diff --git a/contrib/hbwin/hbwin.hbx b/contrib/hbwin/hbwin.hbx
index 18b541cc2e..4b40e41295 100644
--- a/contrib/hbwin/hbwin.hbx
+++ b/contrib/hbwin/hbwin.hbx
@@ -432,6 +432,7 @@ DYNAMIC __oleIsDisp
 DYNAMIC __oleVariantGetType
 DYNAMIC __oleVariantGetValue
 DYNAMIC __oleVariantNew
+DYNAMIC __oleVariantNil2Null
 DYNAMIC __oleVariantNullDate
 DYNAMIC __wapi_DEVMODE_Get
 DYNAMIC __wapi_DEVMODE_New
diff --git a/contrib/hbwin/olecore.c b/contrib/hbwin/olecore.c
index 3014112c26..018788e2ba 100644
--- a/contrib/hbwin/olecore.c
+++ b/contrib/hbwin/olecore.c
@@ -86,6 +86,7 @@ typedef struct
 {
    HRESULT lOleError;
    HB_BOOL fNullDate;
+   HB_BOOL fNil2Null;
    int     iInit;
 } HB_OLEDATA, * PHB_OLEDATA;
 
@@ -93,6 +94,10 @@ static void hb_oleDataInit( void * cargo )
 {
    PHB_OLEDATA pOleData = ( PHB_OLEDATA ) cargo;
 
+   /* default settings: */
+   pOleData->fNullDate = HB_FALSE;
+   pOleData->fNil2Null = HB_FALSE;
+
 #if defined( HB_OS_WIN_CE )
    if( CoInitializeEx( NULL, COINIT_APARTMENTTHREADED ) == S_OK )
 #else
@@ -148,6 +153,17 @@ static HB_BOOL hb_oleGetNullDateFlag( void )
 }
 
 
+static void hb_oleSetNil2NullFlag( HB_BOOL fNil2Null )
+{
+   hb_getOleData()->fNil2Null = fNil2Null;
+}
+
+static HB_BOOL hb_oleGetNil2NullFlag( void )
+{
+   return hb_getOleData()->fNil2Null;
+}
+
+
 static void hb_olecore_init( void * cargo )
 {
    HB_SYMBOL_UNUSED( cargo );
@@ -799,6 +815,7 @@ static void hb_oleItemToVariantRef( VARIANT * pVariant, PHB_ITEM pItem,
       case HB_IT_TIMESTAMP:
       {
          double dDate = hb_itemGetTD( pItem );
+
          if( dDate == 0 && hb_oleGetNullDateFlag() )
          {
             V_VT( pVariant ) = VT_NULL;
@@ -896,6 +913,11 @@ static void hb_oleItemToVariantRef( VARIANT * pVariant, PHB_ITEM pItem,
          }
          break;
 
+      case HB_IT_NIL:
+         if( hb_oleGetNil2NullFlag() )
+            V_VT( pVariant ) = VT_NULL;
+         /* fallthrough */
+
       default:
          if( pVarRef )
          {
@@ -2602,7 +2624,7 @@ HB_FUNC( __OLEVARIANTNEW )
       hb_errRT_OLE( EG_ARG, 1018, 0, NULL, HB_ERR_FUNCNAME, NULL );
 }
 
-/* __oleVariantNullDate( [<lNewNullFlag>] ) -> <lPrevNullFlag> */
+/* __oleVariantNullDate( [<lNewNullDateFlag>] ) -> <lPrevNullDateFlag> */
 HB_FUNC( __OLEVARIANTNULLDATE )
 {
    hb_retl( hb_oleGetNullDateFlag() );
@@ -2610,6 +2632,14 @@ HB_FUNC( __OLEVARIANTNULLDATE )
       hb_oleSetNullDateFlag( hb_parl( 1 ) );
 }
 
+/* __oleVariantNil2Null( [<lNewNil2NullFlag>] ) -> <lPrevNil2NullFlag> */
+HB_FUNC( __OLEVARIANTNIL2NULL )
+{
+   hb_retl( hb_oleGetNil2NullFlag() );
+   if( HB_ISLOG( 1 ) )
+      hb_oleSetNil2NullFlag( hb_parl( 1 ) );
+}
+
 HB_CALL_ON_STARTUP_BEGIN( _hb_olecore_init_ )
    hb_vmAtInit( hb_olecore_init, NULL );
 HB_CALL_ON_STARTUP_END( _hb_olecore_init_ )