diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index c4b63bcdb3..f8ff5f131a 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,12 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2009-08-20 10:44 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
+  * config/global.mk
+    + Don't attempt to install includes and docs if HB_INSTALL_PREFIX
+      is set to source tree root. (to suppress 'cannot copy file to itself'
+      warnings)
+
 2009-08-20 09:55 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
   * utils/hbmk2/hbmk2.prg
   * config/global.mk
diff --git a/harbour/config/global.mk b/harbour/config/global.mk
index 0229a9a4ba..85ac99eb96 100644
--- a/harbour/config/global.mk
+++ b/harbour/config/global.mk
@@ -947,6 +947,7 @@ export HB_PKGNAME
 export HB_PKGNAMI
 
 HB_INSTALL_PREFIX_ORI := $(HB_INSTALL_PREFIX)
+HB_INSTALL_PREFIX_TOP := $(subst /,$(DIRSEP),$(realpath $(TOP)$(ROOT)))
 ifeq ($(HB_BUILD_PKG),yes)
    ifeq ($(HB_INIT_DONE),)
       export HB_TOP := $(subst /,$(DIRSEP),$(realpath $(TOP)$(ROOT)))
@@ -1028,12 +1029,16 @@ ifneq ($(HB_INSTALL_PREFIX),)
       export HB_LIB_INSTALL := $(HB_INSTALL_PREFIX)$(DIRSEP)lib$(LIBPOSTFIX)
    endif
    ifeq ($(HB_INC_INSTALL),)
-      export HB_INC_INSTALL := $(HB_INSTALL_PREFIX)$(DIRSEP)include$(INCPOSTFIX)
+      ifneq ($(HB_INSTALL_PREFIX),$(HB_INSTALL_PREFIX_TOP))
+         export HB_INC_INSTALL := $(HB_INSTALL_PREFIX)$(DIRSEP)include$(INCPOSTFIX)
+      endif
    endif
    ifeq ($(HB_DOC_INSTALL),)
       # Don't set doc dir for *nix targets
       ifeq ($(HB_OS_UNIX),no)
-         export HB_DOC_INSTALL := $(HB_INSTALL_PREFIX)$(DIRSEP)doc
+         ifneq ($(HB_INSTALL_PREFIX),$(HB_INSTALL_PREFIX_TOP))
+            export HB_DOC_INSTALL := $(HB_INSTALL_PREFIX)$(DIRSEP)doc
+         endif
       endif
    endif
 endif