Index: /trunk/src/VBox/Additions/common/VBoxService/Makefile.kmk
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxService/Makefile.kmk	(revision 29530)
+++ /trunk/src/VBox/Additions/common/VBoxService/Makefile.kmk	(revision 29531)
@@ -44,5 +44,5 @@
  VBoxService_DEFS        += VBOX_WITH_MEMBALLOON
 endif
-ifdef VBOX_WITH_PAGE_SHARING
+if1of ($(KBUILD_TARGET), win)
  VBoxService_DEFS        += VBOX_WITH_PAGE_SHARING
 endif
@@ -65,5 +65,5 @@
  	VBoxServiceBalloon.cpp
 endif
-ifdef VBOX_WITH_PAGE_SHARING
+if1of ($(KBUILD_TARGET), win)
  VBoxService_SOURCES    += \
  	VBoxServicePageSharing.cpp