diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index bf319c0b7a..95310c7001 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -8,6 +8,13 @@
    2002-12-01 13:30 UTC+0100 Foo Bar <foo.bar@foobar.org>
 */
 
+2008-02-21 22:17 UTC+0100 Marek Paliwoda (mpaliwoda at interia pl)
+  * harbour/make_vc.mak
+    + Added a possiblity to compile harbour in ST or MT mode by using
+      an environment variable called HB_BUILD_ST. Setting HB_BUILD_ST
+      to yes, causes Harbour+RTL+VM to be built in ST mode. Otherwise
+      MT mode is used.
+
 2008-02-20 00:14 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/utils/hbpp/hbpp.c
     ! added hb_setGetDirSeparator()
@@ -47,7 +54,7 @@
    + contrib/hbnf/descendn.c
    - contrib/hbnf/menuto.prg
    + contrib/hbnf/menutonf.prg
-     ! Renamed some files in libnf to not collide 
+     ! Renamed some files in libnf to not collide
        with core source names.
        (Thanks Marek)
 
diff --git a/harbour/make_vc.mak b/harbour/make_vc.mak
index 75fe5190c1..547505202e 100644
--- a/harbour/make_vc.mak
+++ b/harbour/make_vc.mak
@@ -37,6 +37,7 @@
 #                           gtstd (default),gtcgi,gtwin,gtwvt
 #       HB_GT_LIB         - To override the default GT driver
 #                           (search for HB_GT_LIBS for a list of values)
+#       HB_BUILD_ST       - If set to yes builds harbour in SingleThread mode
 #       HB_BUILD_DLL      - If set to yes enables building harbour VM+RTL
 #                           dll in addition to normal static build
 #       HB_BUILD_MODE     - If set to cpp causes to compile in C++ mode
@@ -138,7 +139,10 @@ CFLAGS         = -D"HB_GT_DEFAULT=$(HB_GT_DEFAULT:gt=)" $(CFLAGS)
 CFLAGS         = -D"HB_GT_LIB=$(HB_GT_LIB:gt=)" $(CFLAGS)
 !endif
 #-----------
+if "$(HB_BUILD_ST)" != "yes"
 CFLAGS         = -MT$(DBGMARKER) $(CFLAGS)
+!endif
+#-----------
 
 CLIBFLAGS      = -c $(CFLAGS) $(CLIBFLAGS)
 CLIBFLAGSDLL   = -D__EXPORT__ $(CLIBFLAGS) $(CLIBFLAGSDLL)