diff --git a/ChangeLog.txt b/ChangeLog.txt
index 8a4e7712bf..fe81270daf 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -10,6 +10,18 @@
      * Change, ! Fix, % Optimization, + Addition, - Removal, ; Comment
  */
 
+2015-08-01 13:14 UTC+0200 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * src/vm/asort.c
+    * restored original loop and added different workaround which for
+      the problem in 64 bit MinGW we exploited. It's dummy function call
+      inside a loop so probably link time optimization (LTO is enabled
+      by -O4 in the newest GCC versions) ignore it and the problem will
+      reappear. Anyhow it only temporary solution which should give time
+      to create self contain example and report the problem to MinGW
+      authors - it's highly possible that also other code exploited this
+      problem so be careful with MinGW64.
+    % fixed index range checking to eliminate unnecessary index verification
+
 2015-08-01 01:28 UTC+0200 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
   * src/vm/asort.c
     * added workaround for bug in 64 bit MinGW builds
diff --git a/src/vm/asort.c b/src/vm/asort.c
index 00e4266941..2f7bd0db6a 100644
--- a/src/vm/asort.c
+++ b/src/vm/asort.c
@@ -280,9 +280,14 @@ static void hb_arraySortStart( PHB_BASEARRAY pBaseArray, PHB_ITEM pBlock,
    HB_SIZE * pBuffer, * pDest, * pPos, nPos, nTo;
 
    pBuffer = ( HB_SIZE * ) hb_xgrab( sizeof( HB_SIZE ) * 2 * nCount );
-   nPos = nCount;
-   while( nPos-- )
+   for( nPos = 0; nPos < nCount; ++nPos )
+   {
+#ifdef __MINGW64__
+      /* added dummy function call to disable buggy optimization in MinGW64 */
+      hb_gcDummyMark( NULL );
+#endif
       pBuffer[ nPos ] = nStart + nPos;
+   }
 
    if( hb_arraySortDO( pBaseArray, pBlock, pBuffer, &pBuffer[ nCount ], nCount ) )
       pPos = ( pDest = pBuffer ) + nCount;
@@ -290,7 +295,7 @@ static void hb_arraySortStart( PHB_BASEARRAY pBaseArray, PHB_ITEM pBlock,
       pDest = ( pPos = pBuffer ) + nCount;
 
    /* protection against array resizing by user codeblock */
-   if( nStart + nCount >= pBaseArray->nLen )
+   if( nStart + nCount > pBaseArray->nLen )
    {
       if( pBaseArray->nLen > nStart )
       {