diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 5d1ada86df..99b217bc24 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,11 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2009-08-27 08:39 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
+  * config/detfun.mk
+    + Accept 'yes' for HB_INC_* variables. Same meaning as leaving
+      it empty.
+
 2009-08-27 08:27 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
   * config/detfun.mk
   * config/detect.mk
diff --git a/harbour/config/detfun.mk b/harbour/config/detfun.mk
index f2b3836482..8cadf04a91 100644
--- a/harbour/config/detfun.mk
+++ b/harbour/config/detfun.mk
@@ -28,6 +28,9 @@ ifeq ($($(_DET_VAR_HAS_)),)
             ifneq ($(if $(_DET_POS),$(filter $(HB_COMPILER),$(_DET_POS)),ok),)
                ifeq ($(filter $(HB_COMPILER),$(_DET_NEG)),)
                   $(_DET_VAR_HAS_) := $($(_DET_VAR_INC_))
+                  ifeq ($($(_DET_VAR_HAS_)),yes)
+                     $(_DET_VAR_HAS_) :=
+                  endif
                   ifeq ($($(_DET_VAR_HAS_)),)
                      ifeq ($(HB_XBUILD),)
                         $(_DET_VAR_HAS_) := $(_DET_INC_DEFP)