diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index efa1f88f6d..7b91654ae2 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,13 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2009-11-08 12:00 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/include/hbapigt.h
+  * harbour/src/rtl/hbgtcore.c
+  * harbour/src/vm/estack.c
+  * harbour/src/vm/garbage.c
+    ! fixed marking GC items stored in thread local GT windows
+
 2009-11-08 02:43 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/src/vm/set.c
     ! fixed small typos in returned values (FALSE instead of NULL and 0)
diff --git a/harbour/include/hbapigt.h b/harbour/include/hbapigt.h
index e1d502d4aa..e921076c48 100644
--- a/harbour/include/hbapigt.h
+++ b/harbour/include/hbapigt.h
@@ -153,7 +153,7 @@ typedef struct
 
 /* Public interface. These should never change, only be added to. */
 
-extern void hb_gtIsGtRef( void );
+extern void hb_gtIsGtRef( void * );
 
 extern HB_EXPORT void   hb_gtStartupInit( void );
 extern HB_EXPORT void * hb_gtAlloc( void * hGT );
diff --git a/harbour/src/rtl/hbgtcore.c b/harbour/src/rtl/hbgtcore.c
index 787f8c95a9..dce7f8658c 100644
--- a/harbour/src/rtl/hbgtcore.c
+++ b/harbour/src/rtl/hbgtcore.c
@@ -3251,9 +3251,9 @@ PHB_GT hb_gtLoad( const char * szGtName, PHB_GT pGT, PHB_GT_FUNCS pSuperTable )
    return NULL;
 }
 
-void hb_gtIsGtRef( void )
+void hb_gtIsGtRef( void * hGT )
 {
-   PHB_GT pGT = ( PHB_GT ) hb_stackGetGT();
+   PHB_GT pGT = ( PHB_GT ) hGT;
 
    if( pGT )
       HB_GTSELF_MARK( pGT );
diff --git a/harbour/src/vm/estack.c b/harbour/src/vm/estack.c
index 732f69f6a5..4133292f05 100644
--- a/harbour/src/vm/estack.c
+++ b/harbour/src/vm/estack.c
@@ -1296,4 +1296,6 @@ void hb_stackIsStackRef( void * pStackId, PHB_TSD_FUNC pCleanFunc )
 
    if( pCleanFunc )
       hb_stackIsTsdRef( pStack, pCleanFunc );
+
+   hb_gtIsGtRef( pStack->hGT );
 }
diff --git a/harbour/src/vm/garbage.c b/harbour/src/vm/garbage.c
index 4d7c4d1bb5..622784fa8c 100644
--- a/harbour/src/vm/garbage.c
+++ b/harbour/src/vm/garbage.c
@@ -646,7 +646,6 @@ void hb_gcCollectAll( BOOL fForce )
       hb_vmIsStackRef();
       hb_vmIsStaticRef();
       hb_clsIsClassRef();
-      hb_gtIsGtRef();
 
       /* check list of locked block for blocks referenced from
        * locked block